EP2317552A2 - Light-emitting device, method of manufacturing light-emitting device, and illumination device - Google Patents
Light-emitting device, method of manufacturing light-emitting device, and illumination device Download PDFInfo
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- EP2317552A2 EP2317552A2 EP10189480A EP10189480A EP2317552A2 EP 2317552 A2 EP2317552 A2 EP 2317552A2 EP 10189480 A EP10189480 A EP 10189480A EP 10189480 A EP10189480 A EP 10189480A EP 2317552 A2 EP2317552 A2 EP 2317552A2
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- substrate
- light
- pads
- conductor pattern
- emitting device
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L25/00—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof
- H01L25/03—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes
- H01L25/04—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers
- H01L25/075—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers the devices being of a type provided for in group H01L33/00
- H01L25/0753—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers the devices being of a type provided for in group H01L33/00 the devices being arranged next to each other
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/22—Secondary treatment of printed circuits
- H05K3/24—Reinforcing the conductive pattern
- H05K3/241—Reinforcing the conductive pattern characterised by the electroplating method; means therefor, e.g. baths or apparatus
- H05K3/242—Reinforcing the conductive pattern characterised by the electroplating method; means therefor, e.g. baths or apparatus characterised by using temporary conductors on the printed circuit for electrically connecting areas which are to be electroplated
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
- H01L2224/45001—Core members of the connector
- H01L2224/45099—Material
- H01L2224/451—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
- H01L2224/45138—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
- H01L2224/45144—Gold (Au) as principal constituent
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
- H01L2224/4805—Shape
- H01L2224/4809—Loop shape
- H01L2224/48091—Arched
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
- H01L2224/732—Location after the connecting process
- H01L2224/73251—Location after the connecting process on different surfaces
- H01L2224/73265—Layer and wire connectors
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2933/00—Details relating to devices covered by the group H01L33/00 but not provided for in its subgroups
- H01L2933/0008—Processes
- H01L2933/0033—Processes relating to semiconductor body packages
- H01L2933/0066—Processes relating to semiconductor body packages relating to arrangements for conducting electric current to or from the semiconductor body
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/48—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
- H01L33/52—Encapsulations
- H01L33/56—Materials, e.g. epoxy or silicone resin
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/48—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
- H01L33/58—Optical field-shaping elements
- H01L33/60—Reflective elements
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/48—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
- H01L33/62—Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/09—Shape and layout
- H05K2201/09009—Substrate related
- H05K2201/09036—Recesses or grooves in insulating substrate
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
- H05K2201/10007—Types of components
- H05K2201/10106—Light emitting diode [LED]
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/20—Details of printed circuits not provided for in H05K2201/01 - H05K2201/10
- H05K2201/2054—Light-reflecting surface, e.g. conductors, substrates, coatings, dielectrics
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/17—Post-manufacturing processes
- H05K2203/175—Configurations of connections suitable for easy deletion, e.g. modifiable circuits or temporary conductors for electroplating; Processes for deleting connections
Definitions
- Embodiments described herein relate generally to a light-emitting device using a light-emitting element such as light-emitting diode, a method of manufacturing the light-emitting device, and an illumination device to which the light-emitting device is mounted.
- a light-emitting element such as light-emitting diode
- a conventional illumination device disclosed in Jpn. Pat. Appln. KOKAI Pub. No. 2009-54989 comprises a base member, and a plurality of light-emitting devices mounted on the base member.
- Each light-emitting device has a substrate formed of ceramics, and a plurality of light-emitting diodes. The light-emitting diodes are fixed to the substrate with adhesive made of epoxy resin.
- a conventional light-emitting device having a structure in which a plurality of pads, on which light-emitting diodes are mounted, are provided on the substrate, and surfaces of the pads are covered with a light-reflecting layer.
- the light-reflecting layer is formed on the surfaces of the pads by subjecting the pads to electroplating.
- Electroplating has advantages of good close contact of metal coating with product to be treated, and inexpensive manufacturing cost. In the light-emitting device, however, since a plurality of pads are arranged at intervals on the substrate, when the pads are subjected to electroplating, it is necessary to electrically connect the pads by a dedicated conductor pattern, and maintain all the pads at the same potential.
- the conductor pattern becomes redundant after electroplating is finished. Therefore, it is necessary to perform work in which the conductor pattern is removed from the substrate by boring a number of holes in the substrate along the conductor pattern, and electrical connection between the pads by the conductor pattern is severed.
- the work of boring holes in the substrate has a large number of steps, and requires much time and labor. This decreases productivity and increases the cost of producing the light-emitting device.
- a light-emitting device comprises a substrate, a plurality of pads, and a plurality of light-emitting elements.
- the pads have conductivity, and are arranged on the substrate.
- a reflecting layer formed by electroplating is provided on surfaces of the pads.
- the light-emitting elements are mounted on the respective pads.
- a depressed part remains on the substrate. The depressed part is formed in the substrate by removing a pattern on the substrate, which is electrically connected with the pads.
- the substrate is preferably formed of material which has thermal conductivity lower than that of metal. However, it is possible to use a substrate having a core material formed of metal which has excellent thermal conductivity such as aluminum.
- the pads are preferably used as wiring pattern which supplies electric current to the light-emitting elements, the pads are not limited to being used as wiring pattern. Specifically, there are cases where it is sufficient that the pads have a function of reflecting light emitted by the light-emitting devices, or a function as heat spreader which spreads heat generated by the light-emitting elements.
- the light-emitting elements it is possible to use semiconductor light-emitting elements such as light-emitting diode chips.
- the light-emitting elements can be mounted on the substrate by, for example, the chip-on-board method or surface mount method.
- the method of mounting the light-emitting elements on the substrate is not specifically limited.
- the specific number of light-emitting elements and pads is not specifically limited.
- the pattern which is removed from the substrate is used for maintaining all the pads at the same potential when the pads are subjected to electroplating.
- the depressed part is a mark left on the substrate after the pattern is removed from the substrate, and the shape and the size of the depressed part are not specifically limited.
- a first embodiment will be described hereinafter with reference to FIG. 1 to FIG. 10 .
- FIG. 1 to FIG. 8 illustrate a light-emitting device 1 which serves as illumination light source.
- the light-emitting device 1 comprises a substrate 2, a plurality of light-emitting elements 3, a plurality of sealing members 4, and a protective cover 5.
- the substrate 2 is formed of synthetic resin material, such as glass epoxy resin, which has thermal conductivity lower than that of metal.
- the material of the substrate 2 is not limited to glass epoxy resin, by other synthetic resin materials or ceramics materials can be used for the substrate 2.
- the substrate 2 is preferably formed of material which has thermal conductivity lower than that of metal, it is possible to adopt a substrate which has a core material formed of metal having excellent thermal conductivity such as aluminum.
- the substrate 2 has an elongated shape which has a pair of long sides 2a and 2b, and a pair of short sides 2c and 2d.
- the substrate 2 has a first surface 6a, and a second surface 6b positioned opposite to the first surface 6a.
- the first and the second surfaces 6a and 6b are flat surfaces.
- a first conductor pattern 7 and a second conductor pattern B are formed on the first surface 6a of the substrate 2.
- the first conductor pattern 7 have a plurality of pads 9 and an power supply conductor 10.
- Each pad 9 has an almost pentagonal shape in which one end is pointed.
- the pads 9 are arranged in 12 columns at intervals in the longitudinal direction of the substrate 2, and arranged in 4 rows at intervals in a direction perpendicular to the longitudinal direction of the substrate 2.
- forty-eight pads 9 are regularly arranged in rows and columns on the first surface 6a of the substrate 2.
- the forty-eight pads 9 form twelve pad columns 13 which are arranged at intervals in the longitudinal direction of the substrate 2.
- Each pad column 13 has four pads 9 arranged in the direction perpendicular to the longitudinal direction of the substrate 2.
- the pad columns 13 are divided into six pad columns 13 which are positioned on the right side of a center line 01, which runs through the center of the longitudinal direction of the substrate 2, and six pad columns 13 which are positioned on the left side of the center line 01.
- the pad columns 13 positioned on the right side of the center line 01 and the pad columns 13 positioned on the left side of the center line 01 are arranged symmetrically with respect to the center line 01.
- each of three pads 9 other than one pad 9 adjacent to the long side 2a of the substrate 2 has a wire connecting part 14.
- Each wire connecting part 14 has a straight-line shape, and extends from an edge of the pad 9 in the direction perpendicular to the longitudinal direction of the substrate 2. A distal end of the wire connecting part 14 is positioned directly before the adjacent pad 9.
- the power supply conductor 10 includes a plurality of first power supply patterns 15, a second power supply pattern 16 which has a cathode terminal 11a and a third power supply pattern 17 which has an anode terminal 11b.
- Each of the first power supply patterns 15 is arranged between adjacent pad columns 13.
- the second power supply pattern 16 extends along the long side 2b of the substrate 2, in the center part of the substrate 2 along the longitudinal direction of the substrate 2.
- the third power supply pattern 17 extends over the whole length of the substrate 2 to run along the long side 2a of the substrate 2, and connects two pad columns 13 which are arranged at both ends of the longitudinal direction of the substrate 2.
- the cathode terminal 11a and the anode terminal 11b are positioned on the center line 01 of the substrate 2.
- the cathode terminal 11a and the anode terminal 11b are electrically connected to a power supply circuit through lead lines.
- the first conductor pattern 7 including the pads 9 has a three-layer structure including a copper layer 20, a nickel plating layer 21, and a silver plating layer 22.
- the copper layer 20 is formed by etching a copper foil deposited on the first surface 6a of the substrate 2.
- the nickel plating layer 21 is formed on the copper layer 20, by subjecting the copper layer 20 to electroplating.
- the silver plating layer 22 is formed on the nickel plating layer 21, by subjecting the nickel plating layer 21 to electroplating.
- the silver plating layer 22 covers the nickel plating layer 21, and forms a reflecting layer exposed on the surface of the first conductor pattern 7. Therefore, the surface of the first conductor pattern 7 is a light-reflecting surface.
- the total light reflectance of the light-reflecting surface is, for example, 90%.
- the second conductor pattern 8 is used for maintaining all the pads 9 at the same potential, when the pads 9 of the first conductor pattern 7 are subjected to electroplating.
- the second conductor pattern 8 has a common line 24 and a plurality of branch lines 25.
- the common line 24 extends in a straight line over the whole length of the substrate 2 to run along the long side 2b of the substrate 2.
- the common line 24 is distant from an end edge of the substrate 2, which defines the long side 2b of the substrate 2, by a predetermined distance D.
- the common line 24 is preferably formed in a straight-line shape, but may be formed in, for example, an arc shape or a meandering shape.
- the branch lines 25 are branched from the common line 24, and extend in a straight line toward spaces between adjacent pad columns 13. Distal ends of the branch lines 25 are connected to the respective pads 9 of the pad columns 13. Therefore, all the pads 9 are electrically connected to the common line 24 through the branch lines 25.
- the second conductor pattern 8 is formed on the first surface 6a of the substrate 2 simultaneously with the first conductor pattern 7, and has a three-layer structure similar to that of the first conductor pattern 7. Specifically, as illustrated in FIG. 4 , the second conductor pattern 8 includes the copper layer 20, the nickel plating layer 21, and the silver plating layer 22. The silver plating layer 22 is exposed on the surface of the second conductor pattern 8. Therefore, the surface of the second conductor pattern 8 is also a light-reflecting surface.
- light-emitting diode chips are used as the light-emitting elements 3.
- the light-emitting diode chips are, for example, InGaN-based elements, and includes sapphire board which has light transmittance, and a light-emitting layer which is deposited on the sapphire board and emits blue light.
- the light-emitting layer is formed by depositing an N-type nitride semiconductor layer, an InGaN light-emitting layer, and a P-type nitride semiconductor layer each other.
- each of the light-emitting diode chips includes a positive electrode and a negative electrode, which supply electric current to the light-emitting layer.
- the positive electrode has a P-type electrode pad which is formed on the P-type nitride semiconductor layer.
- the negative electrode has an N-type electrode pad which is formed on the N-type nitride semiconductor layer.
- the light-emitting elements 3 are individually mounted on the silver plating layer 22 serving as the surfaces of the respective pads 9, by using an adhesive 26 formed of silicone resin. Therefore, in the first embodiment, forty-eight light-emitting elements 3 are regularly arranged in rows and columns on the first surface 6a of the substrate 2. The light-emitting elements 3 are smaller in shape than the pads 9. Therefore, the light-reflecting pads 9 project around the light-emitting elements 3 on the first surface 6a of the substrate 2.
- each light-emitting element 3 is electrically connected to the pad 9, to which the light-emitting element 3 is affixed, through a bonding wire 28.
- the negative electrode of each light-emitting element 3 is electrically connected to the wire connecting part 14 of the adjacent pad 9, through another bonding wire 29.
- the negative electrode of the light-emitting element 3 which is affixed to the pad 9 adjacent to the long side 2b of the substrate 2 is electrically connected to the second power supply pattern 16 through the bonding wire 29.
- the negative electrode of the light-emitting element 3 which is affixed to the pad 9 adjacent to the long side 2b of the substrate 2 is electrically connected to the first power supply pattern 15 through the bonding wire 29.
- the light-emitting elements 3 are connected in series in each pad column 13, and form twelve light-emitting element columns which correspond to the pad columns.
- the twelve light-emitting element columns are connected in parallel with the second power supply pattern 16 and the third power supply pattern 17.
- gold wires are used as the bonding wires 28 and 29.
- the bonding wires 28 and 29 are connected to the positive electrodes and the negative electrodes of the light-emitting elements 3 through bumps mainly formed of gold (Au), to improve the mounting strength of the bonding wires 28 and 29 and reduce damage to the light-emitting elements 3.
- a groove-like depressed part 33 is formed in the first surface 6a.
- the depressed part 33 is a trace which is left after the common line 24 is removed, and extends in a straight line along the long side 2b of the substrate 2.
- the depressed part 33 is positioned between the end edge of the substrate 2 which defines the long side 2b of the substrate 2 and the first power supply patterns 15 on the substrate 2, and is distant from the end edge of the substrate 2 by the predetermined distance.
- the depressed part 33 is defined by a bottom surface 33a and a pair of side surfaces 33b and 33c, and opened to the first surface 6a of the substrate 2.
- the depressed part 33 is painted with black color to clearly distinguish the depressed part 33 from the second conductor pattern 8.
- a creepage distance between the end edge of the substrate 2 which defines the long side 2b of the substrate 2 and the first power supply patterns 15 on the substrate 2 is a value obtained by adding the height of the side surfaces 33b and 33c of the depressed part 33. Therefore, the creepage distance is longer than the clearance between the end edge of the substrate 2 and the first conductor pattern 7 by the depth of the depressed part 33.
- the shape of the depressed part 33 is not limited to the first embodiment.
- the depressed part 33 may have a V-shaped or U-shaped cross section in the direction perpendicular to the longitudinal direction of the substrate 2.
- the sealing members 4 are elements for sealing the individual light-emitting elements 3 and the bonding wires 28 and 29 connected to the light-emitting elements 3 on the pads 9, and rise in a hemispherical shape from the respective pads 9.
- transparent silicone resin having light transmittance is used as the sealing members 4.
- the silicone resin is applied in a liquid state onto each pad 9.
- the applied silicone resin is cured by heating or natural drying, and held on each pad 9.
- the sealing member 4 contains fluorescent material.
- the fluorescent material is uniformly dispersed in the sealing members 4.
- As the fluorescent material, used is yellow fluorescent material which is excited by blue light emitted by the light-emitting elements 3 and emits yellow light.
- the fluorescent material mixed into the sealing members 4 is not limited to yellow fluorescent material.
- red fluorescent material which is excited by blue light and emits red light, or green fluorescent material which emits green light, to the sealing members 4.
- the protective cover 5 covers the substrate 2 on which the light-emitting elements 3 are sealed.
- the protective cover 5 is formed of synthetic resin material having light transmittance, such as transparent acrylic resin and polycarbonate resin.
- the protective cover 5 includes a receptacle 35 into which the substrate 2 is fitted.
- the receptacle 35 has a bottom surface 35a which is opposed to the first surface 6a of the substrate 2, and an opening end 35b which is opposed to the bottom surface 35a.
- the opening end 35b of the receptacle 35 is opened to a back surface 5a of the protective cover 5.
- a plurality of depressions 36 are formed in the bottom surface 35a of the receptacle 35.
- the depressions 36 are arranged in rows and columns on the bottom surface 35a to correspond to the respective light-emitting elements 3.
- the depressions 36 have a conic shape which has a circular opening part opened to the bottom surface 35a, and are opposed to the respective sealing members 4 covering the light-emitting elements 3.
- the spherical top parts of the sealing members 4 get into the respective depressions 36 through the opening parts of the depressions 36.
- the protective cover 5 has a flange part 37.
- the flange part 37 surrounds the opening end 35b of the receptacle 35, and projects from the outer peripheral surface of the protective cover 5 to the outside of the protective cover 5.
- the substrate 2 is fixed within the receptacle 35 of the protective cover 5, by transparent silicone-resin-based adhesive 38.
- the adhesive 38 is filled into a space between the first surface 6a of the substrate 2 and the bottom surface 35a of the receptacle 35.
- the opening parts of the depressions 36 are closed with the sealing members 4 and the adhesive 38.
- the inside parts of the depressions 36 become closed spaces, and an air layer 39 is formed between the protective cover 5 and the sealing members 4.
- the second surface 6b of the substrate 2 is positioned inside the receptacle 35 more than the back surface 5a of the protective cover 5 does.
- the first conductor pattern 7 and the second conductor pattern 8 are formed on the first surface 6a of the substrate 2. Specifically, the foil deposited on the first surface 6a is etched, and thereby a copper layer 20 of the first conductor pattern 7 and a copper layer 20 of the second conductor pattern 8 are formed. Among the copper layer 20 of the first conductor pattern 7, parts which form the pads 9 are electrically connected to each other through the copper layer 20 of the second conductor pattern 8. Therefore, all the parts of the copper layer 20 of the first conductor pattern 7, which form the pads 9, are maintained at the same potential.
- the copper layers 20 of the first and the second conductor patterns 7 and 8 are subjected to electroplating, and thereby a nickel plating layer 21 is formed on the copper layers.
- the nickel plating layer 21 is subjected to electroplating, and thereby a silver plating layer 22 is formed on the nickel plating layer 21.
- all the parts which form the pads 9 in the copper layer 20 of the first conductor pattern 7 are maintained at the same potential.
- the nickel plating layer 21 and the silver plating layer 22 are formed on the copper layer 20 of the first conductor pattern 7, by using the copper layer 20 of the first conductor pattern 7 as cathode, using the same metal as plating layer as anode, and causing an electric current to flow between the cathode and the anode.
- the nickel plating layer 21 and the silver plating layer 22 are also formed on the copper layer 20 of the second conductor pattern 8 simultaneously with the first conductor pattern 7.
- the common line 24 of the second conductor pattern 8 is removed from the first surface 6a of the substrate 2. Specifically, the common line 24 on the first surface 6a is scraped away by using an electrical tool such as a router and a trimmer. As a result, electrical connection between the pads 9 of the first conductor pattern 7 and the common line 24 is severed, and the pads 9 become electrically independent.
- a groove-like depressed part 33 is formed in the first surface 6a.
- the depressed part 33 crosses over the bases of the branch lines 25 branching off from the common line 24.
- the branch lines 25 are left on the first surface 6a of the substrate 2, in a state of being electrically separated from each other.
- each light-emitting element 3 is affixed on the respective pads 9 of the first conductor pattern 7. Then, the positive electrode of each light-emitting element 3 is electrically connected to the pad 9, to which the light-emitting element 3 is affixed, by bonding wire 28. In the same manner, the negative electrode of each light-emitting element 3 is connected to the wire connecting part 14 of the adjacent pad 9 and the first power supply pattern 15 by bonding wire 29.
- sealing members 4 are individually applied onto the respective pads 9 to which the light-emitting elements 3 are affixed, to cover the light-emitting elements 3 and the bonding wires 28 and 29 connected to the light-emitting elements 3 with the sealing members 4. Thereafter, the applied sealing members 4 are cured. Thereby, the light-emitting elements 3 and the bonding wires 28 and 29 are sealed on the first surface 6a of the substrate 2 by the sealing members 4'.
- the protective cover 5 is held in a position in which the bottom surface 33a of the receptacle 35 of the protective cover 5 faces upward.
- silicone-based adhesive 38 is applied to the bottom surface 33a of the receptacle 35.
- the substrate 2 on which the light-emitting elements 3 are sealed is deposited in the receptacle 35 of the protective cover 5, and the hemispherical sealing members 4 covering the light-emitting elements 3 are positioned in the opening parts of the depressions 36.
- the first surface 6a of the substrate 2 is affixed to the bottom surface 35a of the receptacle 35 by the silicone-based adhesive 38, and the substrate 2 is united with the protective cover 5. Thereby, a series of manufacturing steps of the light-emitting device 1 is finished.
- the illumination device 41 which uses the light-emitting device 1 as light source will be explained hereinafter, with reference to FIG. 9 and 10 in addition to the above drawings.
- the illumination device 41 is used by directly attaching the illumination device 41 to, for example, the indoor ceiling C.
- the illumination device 41 comprises a base 42, and two light-emitting devices 1.
- the base 42 is an example of a main body of the illumination device 41, and formed in a rectangular shape by using metal material such as aluminum.
- the base 42 is fixed to the ceiling C by bolts.
- the two light-emitting devices 1 are arranged in a straight line along a longitudinal direction of the base 42, and are electrically connected to a power supply unit (not shown) including a power supply circuit.
- a power supply unit (not shown) including a power supply circuit.
- Each light-emitting device 1 is fixed to the base 2 by a plurality of screws 43.
- the screws 43 are screwed into the base 2 through the flange part 37 of the protective cover 5. Therefore, the protective cover 5 also functions as bracket to fix the light-emitting devices 1 to the base 42.
- the back surface 5a of the protective cover 5 contacts the base 42, and the opening end 35b of the receptacle 35 is closed by the base 42.
- the second surface 6b of the substrate 2, which is received into the receptacle 35 goes inside the receptacle 35 more than the back surface 5a of the protective cover 5 does, as illustrated in FIG. 2 . Therefore, the second surface 6b of the substrate 2 is distant from the base 42.
- a space between the substrate 2 and the base 42 functions as a thermal insulating layer 44.
- the thermal insulating layer 44 is not limited to the space.
- a thermal insulating material may be filled into the space between the substrate 2 and the base 42.
- the illumination device 41 having the above structure, a voltage is applied to the two light-emitting devices 1 through the power supply unit. As a result, the light-emitting elements 3 on the substrate 2 emit light all together. The blue light emitted by the light-emitting elements 3 is made incident on the sealing members 4. Part of the blue light made incident on the sealing members 4 is absorbed into the yellow fluorescent material. The rest of the blue light passes through the sealing members 4, without being absorbed into the yellow fluorescent material.
- the yellow fluorescent material which has absorbed the blue light is excited and emits yellow light. Since yellow light passes through the sealing members 4, the yellow light and the blue light are mixed each other inside the sealing members 4, and become white light.
- the white light passes through the protective cover 5 through the air layer 39, and is guided to the outside of the light-emitting device 1.
- the light-emitting device 1 serves as a surface light source which emits white light.
- the white light emitted by the light-emitting device 1 is used for illuminating the inside of the room from the ceiling.
- the pads 9 functions as heat spreader which spreads heat conducted from the light-emitting elements 3.
- the heat which is spread by the pads 9 is mainly conducted from the pads 9 to the protective cover 5, and radiated from the protective cover 5 to the outside of the light-emitting devices 1. Therefore, thermal transmission from the second surface 6b of the substrate 2 to the base 42 of the illumination device 41 is suppressed, and the heat of the light-emitting elements 3 is not easily conducted to the ceiling C.
- the substrate 2 is formed of synthetic resin material which has thermal conductance lower than that of metal.
- the thermal insulating layer 44 is interposed between the substrate 2 and the base 42. As a result, thermal transmission from the substrate 2 to the base 42 is suppressed, and thermal transmission from the substrate 2 to the protective cover 5 is promoted. Therefore, the heat of the light-emitting elements 3 can be positively radiated from the protective cover 5.
- the pads 9, to which the light-emitting elements 3 are affixed project around the light-emitting elements 3.
- the pads 9 have light reflectance by virtue of presence of the silver plating layer 22. Therefore, most of light going from the light-emitting elements 9 toward the substrate 2 is reflected by the silver plating layer 22, and guided to a direction in which the light is to be taken out. Thus, the light emitted by the light-emitting elements 3 can be efficiently taken out of the light-emitting devices 1.
- the depressions 36 of the protective cover 5 form the air layer 39 between the sealing members 4 covering the light-emitting elements 3 and the protective cover 5.
- the light of the light-emitting elements 3 which is transmitted through the sealing members 4 is diffused when it passes through the interface between the air layer 39 and the protective cover 5.
- the diffused light is transmitted through the protective cover 5, and radiated to the outside of the light-emitting device 1. Therefore, the luminance of the surface of the protective cover 5 is made uniform, and the light-emitting device 1 has good appearance while the light-emitting device 1 is lit.
- the light-emitting device 1 includes the light-transmitting protective cover 5 which covers the substrate 2 and the light-emitting elements 3. Therefore, when the light-emitting device 1 is used as light source of the illumination device 41, it is possible to eliminate a shade and a globe from the illumination device 41. This enables simplifying the structure of the illumination device 41.
- the substrate 2 to which the light-emitting elements 3 are affixed is contained in the receptacle 35 of the protective cover 5, and affixed to the bottom surface 35a of the receptacle 35 by the adhesive 38.
- the adhesive 38 is filled into the space between the bottom surface 35a of the receptacle 35 and the substrate 2, and surrounds the sealing members 4. This structure prevents dust and water from infiltrating the space between the substrate 2 and the protective cover 5. Therefore, the sealing members 4, through which the light of the light-emitting elements 3 is transmitted, are not easily soiled, and it is possible to add a waterproof function to the illumination device 41.
- the sealing members 4 are applied to the substrate 2, to individually cover the forty-eight light-emitting elements 3 and the bonding wires 28 and 29 which are connected to the respective light-emitting elements 3. Therefore, it is possible to reduce the quantity of the silicone resin and the fluorescent material added to the silicone resin, in comparison with the case where all the light-emitting elements 3 are continuously covered with silicone resin. This is advantageous for suppressing the cost of the light-emitting device 1.
- the second conductor pattern 8 which maintains all the pads 9 at the same potential when the pads 9 of the first conductor pattern 7 are subjected to electroplating, is formed of the common line 4 and a plurality of branch lines 25 which connect the common line 24 to the pads 9.
- the common line 24 has a simple shape which extends in a straight line along the long side 2b of the substrate 2, the common line 24 can be scraped off by simply moving the electrical tool in a straight line along the common line 24. Therefore, it is possible to efficiently and easily perform work of removing the common line 24 from the substrate 2, and improve the productivity of the light-emitting device 1.
- the groove-like depressed part 33 which is left after the common line 24 is scraped off is distant from the end edge of the substrate 2, which defines the long side 2b of the substrate 2, by the predetermined distance, and is positioned between the end edge of the substrate 2 and the first power supply patterns 15 on the substrate 2.
- the creepage distance between the end edge of the substrate 2 and the first power supply patterns 15 becomes longer than the clearance between the end edge of the substrate 2 and the first power supply patterns 15, by a length corresponding to the depth of the depressed part 33. Therefore, when an electrical-conductive element is positioned around the substrate 2, it is possible to secure an insulating distance between the electrical-conductive element and the first power supply patterns 15, and dielectric strength of the substrate 2 is improved.
- FIG. 11 discloses an illumination device 51 according to a second embodiment.
- the illumination device 51 uses three light-emitting devices 1 as light source.
- the structure of the light-emitting device 1 is the same as that of the first embodiment.
- a protective cover is omitted to show the internal structure of the light-emitting devices 1.
- the illumination device 51 includes a case 52 which is surface-mounted on the ceiling.
- the case 52 is an example of a main body of the illumination device 51.
- the case 52 has an elongated box shape, and has an elongated opening part 53 which is opened downward.
- the three light-emitting devices 1 and a power supply unit which lights the three light-emitting devices 1 are contained in the case 52.
- the light-emitting devices 1 are arranged in line along a longitudinal direction of the case 52.
- the protective cover of each light-emitting device 1 is exposed from the opening part 53 of the case 52 to the outside of the case 52. In other words, the protective cover of each light-emitting device 1 covers the opening part 53 of the case 52 from the inside of the case 52. Therefore, the case 52 does not need a dedicated translucent cover which covers the opening part 53.
- the illumination device 51 which has the same effect as that of the first embodiment.
- FIG. 12 to FIG. 18 disclose a light-emitting device 61 according to a third embodiment.
- the light-emitting device 61 which serves as illumination light source comprises a substrate 62, a plurality of light-emitting elements 63, and a pair of sealing members 64a and 64b.
- the substrate 62 is formed of a synthetic resin material such as glass epoxy resin.
- the substrate 62 has an elongated shape which has a pair of long sides 62a and 62b, and a pair of short sides 62c and 62d.
- the substrate 62 has a first surface 65a, a second surface 65b positioned opposite to the first surface 65a, and an outer peripheral surface 65c which connects the first surface 65a with the second surface 65b.
- the first and the second surfaces 65a and 65b are flat surfaces.
- a length of the substrate 62 along the long sides 62a and 62b is 230 mm, and a width of the substrate 62 along the short sides 62c and 62d is 35 mm.
- a thickness of the substrate 62 is preferably 0.5 mm to 1.8 mm. In the second embodiment, the substrate 62 having a thickness of 1.0 mm is used.
- a plurality of piercing parts 66 are formed at end edges which define the long sides 62a and 62b of the substrate 62.
- the piercing parts 66 are arc-shaped cut-away portions which are opened to the outer peripheral surface 63c of the substrate 62, and pierce through the substrate 62 in a thickness direction.
- the piercing parts 66 are arranged at intervals in the longitudinal direction of the substrate 62.
- a plurality of screws 68 are inserted through the respective piercing parts 66.
- the screws 68 are an example of fixing parts which fix the substrate 62 to a base of the illumination device, and are screwed into the base through the piercing parts 66.
- the end edge of the substrate 62 is held between head parts of the screws 68 and the base. Thereby, the substrate 62 is fixed to the base.
- a first conductor pattern 70 and a second conductor pattern 71 are formed on the first surface 65a of the substrate 62.
- the first conductor pattern 70 includes, for example, nine pads 72, a positive power supply conductor 73, a negative power supply conductor 74, and a relay conductor 75.
- the pads 72 have a rectangular shape, and are arranged in line at intervals in the longitudinal direction of the substrate 62.
- Each pad 72 is divided into a first mounting area 76a and a second mounting area 76b by a slit 72a.
- the slit 72a extends in the center part of the pad 72 in a straight line in the longitudinal direction of the substrate 62, and is opened to one end of the pad 72.
- Six depressed parts 77 are formed in the first mounting area 76a of each pad 72.
- the depressed parts 77 are opened to one side edge of the pad 72, and arranged in line at intervals in the longitudinal direction of the substrate 62.
- six depressed parts 77 are formed in the second mounting area 76b of each pad 72.
- the depressed parts 77 are opened to the slit 72a, and arranged in line at intervals in the longitudinal direction of the substrate 62.
- each of the pads 72 other than one pad 72 positioned at the left end of the substrate 62 has a pair of extension parts 79a and 79b.
- the extension parts 79a and 79b extend in straight line from one end of the pad 72 in the longitudinal direction of the substrate 62, and are arranged in parallel with each other at an interval.
- Each of the extension parts 79a and 79b has six power supply terminals 80.
- the power supply terminals 80 project from the extension parts 79a and 79b, and are arranged in line at intervals in the longitudinal direction of the substrate 62.
- One extension part 79a of each pad 72 extends along one side edge of the adjacent pad 72.
- the power supply terminals 80 of the extension part 79a are inserted into the respective depressed parts 77 opened to one side edge of the pad 72.
- the extension part 79a and the side edge of the pad 72 are electrically separated by providing an insulating space between them.
- the power supply terminals 80 of the extension part 79a and the depressed parts 77 are electrically separated by providing insulating spaces between them.
- each pad 72 is inserted into the slit 72a of the adjacent pad 72.
- the power supply terminals 80 of the extension part 79b are inserted into the respective depressed parts 77 opened to the slit 72a.
- the extension part 79b and the pad 72 are electrically separated by providing an insulating space positioned inside the slit 72a.
- the power supply terminals 80 of the extension part 79b and the depressed parts 77 are electrically separated by providing insulating spaces between them.
- the pads 72 are arranged in line in the longitudinal direction of the substrate 62, in a state where the extension parts 79a and 79b are alternately reversed in the width direction of the substrate 62.
- the positive power supply conductor 73 extends over the whole length of the substrate 62 to run along the long side 62b of the substrate 62.
- the negative power supply conductor 74 extends along the longitudinal direction of the substrate 62 to run along the long side 62b of the substrate 62.
- the left end of the negative power supply conductor 74 is connected to the pad 72 positioned at the left end of the substrate 62.
- the positive power supply conductor 73 has an anode terminal 81.
- the negative power supply conductor 74 has a cathode terminal B2.
- the anode terminal 81 and the cathode terminal 82 are aligned at an interval in the left end part of the substrate 62.
- the relay conductor 75 extends along the longitudinal direction of the substrate 62 to run along the long side 62b of the substrate 62.
- the relay conductor 75 is positioned in a right end part of the substrate 62.
- the relay conductor 75 includes a pair of power supply patterns 84a and 84b.
- the power supply patterns 84a and 84b extend in a straight line in the longitudinal direction of the substrate 62, and are arranged in parallel with each other with a space between them.
- Each of the power supply patterns 84a and 84b has six power supply terminals 85.
- the power supply terminals 85 project from the power supply patterns 84a and 84b, and are arranged in line at intervals in the longitudinal direction of the substrate 62.
- One power supply pattern 84a extends along one side edge of the pad 72 positioned at the right end of the substrate 62.
- the power supply terminals 85 of the power supply pattern 84a are inserted into the respective depressed parts 77 opened to the side edge of the pad 72.
- the power supply pattern 84a and the side edge of the pad 72 are electrically separated by providing an insulating space between them.
- the power supply terminals 85 of the power supply pattern 84a and the depressed parts 77 of the pad 72 are electrically separated by providing insulating spaces between them.
- the other power supply pattern 84b is inserted into the slit 72a of the pad 72 positioned at the right end of the substrate 62.
- the power supply terminals 85 of the power supply pattern 84b are inserted into the respective depressed parts 77 opened to the slit 72a.
- the power supply pattern 84b and the pad 72 are electrically separated by providing an insulating space between them.
- the power supply terminals 85 of the power supply pattern 84b and the depressed parts 77 of the pad 72 are electrically separated by providing insulating spaces between them.
- a power supply connector 86 is soldered to the anode terminal 81 and the cathode terminal 82.
- the power supply connector 86 is positioned on the first surface 65a of the substrate 62, and electrically connected to the power supply circuit through lead lines 86a.
- the negative power supply conductor 74 and the relay conductor 85 are short-circuited through a relay connector 87.
- the first conductor pattern 70 including the pads 72 has a three-layer structure including a copper layer 88, a nickel plating layer 89, and a silver plating layer 90.
- the copper layer 88 is formed by etching a copper foil deposited on the first surface 65a of the substrate 62.
- the nickel plating layer 89 is formed on the copper layer 88 by subjecting the copper layer 88 to electroplating.
- the silver plating layer 90 is formed on the nickel plating layer 89 by subjecting the nickel plating layer 89 to electroplating.
- the silver plating layer 90 covers the nickel plating layer 89, and forms a reflecting layer which is exposed to the surface of the first conductor pattern 70. Therefore, the surface of the first conductor pattern 70 is a light-reflecting surface.
- the nickel plating layer 89 preferably has a thickness of 5 ⁇ m or more.
- the silver plating layer 90 preferably has a thickness of 1 ⁇ m or more. Specifying the thicknesses of the nickel plating layer 89 and the silver plating layer 90 like this solves the problem of variations in thicknesses of the nickel plating layer 89 and the silver plating layer 90, and makes the light reflectance of all the pads 72 uniform.
- the second conductor pattern 71 is used for maintaining all the pads 72 at the same potential when the pads 72 of the first conductor pattern 70 to electroplating.
- the second conductor pattern 71 includes a common line 92 and a plurality of branch lines 93 as illustrated in FIG. 13 .
- the common line 92 extends in a straight line over the whole length of the substrate 62 to run along the long side 62a of the substrate 62. Simultaneously, the common line 92 is distant from the end edge of the substrate 62, which defines the long side 62a of the substrate 62, by a predetermined distance D.
- the common line 92 has a plurality of curved parts 94 in positions corresponding to the piercing parts 66 of the substrate 62.
- the curved parts 94 are curved in arc shape in a direction going away from the edges of the piercing parts 66.
- the common line 92 is distant from the edges of the piercing parts 66, by at least the same distance as the distance D in the parts corresponding to the piercing parts 66.
- the branch lines 93 are branched from the common line 92, and extend in a straight line toward the pads 72.
- the branch lines 93 are arranged at intervals in the longitudinal direction of the substrate 62. Distal ends of the branch lines 93 are electrically connected to all the pads 72 and the power supply pattern 84a of the relay conductor 75. In other words, all the pads 72 and the relay conductor 75 are electrically connected to the common line 92 through the branch lines 93.
- the second conductor pattern 71 is formed on the first surface 65a of the substrate 62 simultaneously with the first conductor pattern 70, and has the same three-layer structure as that of the first conductor pattern 70. Therefore, the surface of the second conductor pattern 71 is formed of a silver plating layer, and has light reflectance.
- Each light-emitting element 63 is a light-emitting diode chip as in the first embodiment, and has a positive electrode and a negative electrode.
- the light-emitting elements 63 are affixed to the first mounting areas 76a and the second mounting areas 76b of the pads 72 by a silicone-resin-based adhesive 96.
- six light-emitting elements 63 are arranged in the first mounting area 76a of each pad 72 in line at intervals in the longitudinal direction of the substrate 62, and six light-emitting elements 63 are arranged in the second mounting area 76b of each pad 72 in line at intervals in the longitudinal direction of the substrate 62. Therefore, each pad 72 includes twelve light-emitting elements 63.
- the light-emitting elements 63 on each pad 72 form two rows of light-emitting elements which are successively arranged in the longitudinal direction of the substrate 62.
- each light-emitting element 63 is electrically connected to the pad 72, to which the light-emitting element 63 is affixed, by a bonding wire 98.
- the negative electrode of each light-emitting element 63 is electrically connected to the power supply terminals 80 of the adjacent pad 72 and the power supply terminals 85 of the power supply patterns 84a and 84b by another bonding wire 99.
- the light-emitting device 61 has nine parallel circuits 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, and 100i, in each of which twelve light-emitting elements 63 are connected in parallel.
- the nine parallel circuits 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, and 100i are connected in series.
- a capacitor 101 is connected to each of the nine parallel circuits 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, and 100i. Simultaneously, a capacitor 101 is also connected to a circuit which connects the parallel circuits 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, and 100i in series.
- the capacitors 101 are mounted on the first surface 65a of the substrate 62.
- the power supply terminals 80 and 85 to which the bonding wire 99 is connected are inserted into the depressed parts 77 of the adjacent pad 72.
- the power supply terminals 80 and 85 go toward the center parts of the first and the second mounting areas 76a and 76b, the light-emitting elements 63 can be affixed to the center parts of the first and the second mounting areas 76a and 76b, without changing the lengths of the bonding wires 98 and 99. Therefore, it is possible to conduct the heat generated by the light-emitting elements 63 to a wide range of the first and the second mounting areas 76a and 76b, and efficiently radiate the heat from the pads 72.
- the second conductor pattern 71 which all the pads 72 at the same potential becomes redundant after the first conductor pattern 70 is subjected to electroplating. Therefore, in the third embodiment, after the first conductor pattern 70 is subjected to electroplating, the common line 92 of the second conductor pattern 71 is removed, to sever electrical connection between the pads 72 obtained by the second conductor pattern 71.
- a depressed part 105 is formed in the first surface 65a of the substrate 62.
- the depressed part 105 is a trace which is left after the common line 92 is removed, and extends along the long side 62a of the substrate 62.
- the depressed part 105 is a groove which is defined by a bottom surface 105a and a pair of side surfaces 105b and 105c, and opened to the first surface 65a of the substrate 62.
- the depressed part 105 has a plurality of curved parts 106 in positions corresponding to the piercing parts 66 of the substrate 62.
- the curved parts 106 are formed in a shape which agrees with the shape of the curved parts 94 of the common line 92, to detour around the piercing parts 66.
- the depressed part 105 having the above structure is positioned between the end edge of the substrate 62, which defines the long side 62a of the substrate 62, and the pads 72, and distant from the end edge of the substrate 62 by a predetermined distance.
- the depressed part 105 has a width of 1 mm, and a depth of 0.3 mm.
- the depressed part 105 By presence of the depressed part 105 as described above, only the branch lines 93 of the second conductor pattern 71 remain on the first surface 65a of the substrate 62. The remaining branch patterns 93 are electrically separated.
- a creepage distance between the end edge of the substrate 62 which defines the long side 62a of the substrate 62 and the pads 72 is a value obtained by adding the height of the side surfaces 105b and 105c of the depressed part 105. Therefore, the creepage distance is longer than the clearance between the end edge of the substrate 62 and the pads 72 by the depth of the depressed part 105.
- the shape of the depressed part 105 is not limited to the third embodiment.
- the depressed part 105 may have a V-shaped or U-shaped cross section in the direction perpendicular to the longitudinal direction of the substrate 62.
- the sealing members 64a and 64b are elements for sealing the light-emitting elements 63, which are arranged in two lines, and the bonding wires 98 and 99 on the pads 72.
- the sealing members 64a and 64b are formed of transparent silicone resin, in which fluorescent material is mixed, and extend in a straight line along the longitudinal direction of the substrate 62.
- the first surface 65a of the substrate 62 is covered with a white resist layer 108, except for areas on which parts such as the light-emitting elements 63 and the capacitors 101 are mounted.
- the resist layer 108 has light reflectance.
- the resist layer 108 continuously covers the first conductor pattern 70, the branch lines 93, and the depressed part 105. Therefore, the first conductor pattern 70, the branch lines 93 and the depressed part 105 on the first surface 65a of the substrate 62 are not easily viewed.
- thermally radiative sheets 110 are deposited on the second surface 65b of the substrate 62.
- the thermally radiative sheets 110 are an example of conductors, and are formed of a copper foil which has excellent heat conductance.
- the thermally radiative sheets 110 are arranged in two lines at intervals in the longitudinal direction of the substrate 62, to correspond to the pads 72 of the first surface 65a.
- the adjacent thermally radiative sheets 110 are thermally separated by a plurality of first slits 111, which extend in the longitudinal direction of the substrate 62, and a plurality of second slits 112 which extend in the direction perpendicular to the longitudinal direction of the substrate 62.
- the thermally radiative sheets 110 and the second surface 65b of the substrate 62 is covered with a resist layer 113.
- the thermally radiative sheets 110 By depositing the thermally radiative sheets 110 on the second surface 65b of the substrate 62, it is possible to equalize temperature distribution of the substrate 62 which receives the heat of the light-emitting elements 63. Therefore, the thermal radiation property of the substrate 62 can be improved.
- the second slits 112 which run along the direction perpendicular to the longitudinal direction of the substrate 62, between the adjacent thermally radiative sheets 110, it is possible to suppress a warp and deformation of the substrate 62 due to heat.
- the first conductor pattern 70 and the second conductor pattern 71 are formed on the first surface 65a of the substrate 62. Specifically, the copper foil deposited on the first surface 65a is etched, and thereby copper layers 88 of the first and the second conductor pattern 70 and 71 are formed. Among the copper layer 88 of the first conductor pattern 70, parts which form the pads 72 are electrically connected to each other through the copper layer 88 of the second conductor pattern 71. Therefore, all the parts of the copper layer 88 of the first conductor pattern 70, which form the pads 72, are maintained at the same potential.
- the copper layer 88 of the first conductor pattern 70 is subjected to electroplating, and thereby a nickel plating layer 89 is formed on the copper layer 88. Thereafter, the nickel plating layer 89 is subjected to electroplating, and thereby a silver plating layer 90 is formed on the nickel plating layer 89.
- all the parts which form the pads 72 in the copper layer 88 of the first conductor pattern 70 are maintained at the same potential.
- the nickel plating layer 89 and the silver plating layer 90 are formed on the copper layer 88 of the first conductor pattern 70, by using the copper layer 88 of the first conductor pattern 70 as cathode, using the same metal as plating layer as anode, and causing an electric current to flow between the cathode and the anode.
- the nickel plating layer 89 and the silver plating layer 90 are also formed on the copper layer 88 of the second conductor pattern 71 simultaneously with the first conductor pattern 70.
- the common line 92 of the second conductor pattern 71 is removed from the first surface 65a of the substrate 62. Specifically, the common line 92 on the first surface 65a is scraped away in the same manner as the first embodiment. As a result, electrical connection between the pads 72 of the first conductor pattern 70 and the second conductor pattern 71 is severed, and the pads 72 are maintained in a state of being electrically independent.
- a groove-like depressed part 105 is formed in the first surface 65a.
- the depressed part 105 has the curved parts 106, which are curved to detour around the piercing parts 66, in positions corresponding to the piercing parts 66 of the substrate 62.
- the depressed part 105 crosses over the bases of the branch lines 93 branching off from the common line 92. As a result, the branch lines 93 are left on the first surface 65a of the substrate 62, in a state of being electrically separated from each other.
- each pad 72 six light-emitting elements 63 are affixed on each of the first and the second mounting areas 76a and 76b of each pad 72. Then, the positive electrodes of the light-emitting elements 63 are electrically connected to the pads 72, to which the light-emitting elements 63 are affixed, by bonding wires 98. In the same manner, the negative electrodes of the light-emitting elements 63 are connected to the power supply terminals 80 of the adjacent pads 72 and the power supply terminals 85 of the power supply patterns 84a and 84b by bonding wires 99.
- the light-emitting elements 63 arranged in two lines and the bonding wires 98 and 99 are sealed on the pads 72 by the sealing members 64a and 64b. Thereby, the light-emitting device 61 as illustrated in FIG. 15 is formed.
- the second conductor pattern 71 which maintains the pads 72 of the first conductor pattern 70 at the same potential is formed of the common line 92 and the branch lines 93 which are branched off from the common line 92 and reach the pads 72. Therefore, electrical connection between the pads 72 obtained by the second conductor pattern 71 can be severed, by removing the common line 92 from the substrate 62.
- the depressed part 105 which is left after the common line 92 is scraped away is distant from the end edge of the substrate 62 by the predetermined distance, and positioned between the end edge of the substrate 62 and the pads 72.
- the creepage distance between the end edge of the substrate 62 and the pads 72 becomes longer than the clearance between the end edge of the substrate 62 and the pads 72, by a length corresponding to the depth of the depressed part 105, and it is possible to secure an insulating distance between the end edge of the substrate 62 and the pads 72.
- the depressed part 105 has the curved parts 106, which are curved to detour around the piercing parts 66, in positions corresponding to the piercing parts 66 of the substrate 62. Therefore, it is possible to equally secure insulating distances from the edges of the piercing parts 66 to the curved parts 106, and increase the dielectric strength of the substrate 62. Thus, even when the screws 68 inserted through the piercing parts 66 are formed of metal, insulation of the screws 68 from the pads 72 can be sufficiently secured, and the reliability of electrical insulation of the light-emitting device 61 can be improved.
- FIG. 19 discloses a fourth embodiment.
- the fourth embodiment is different from the third embodiment, in that a plurality of through-holes 120 are provided in outer edge parts of a substrate 62 running along long sides 62a and 62b.
- the other parts of the structure of a light-emitting device 61 are the same as those of the third embodiment.
- the through-holes 120 of the substrate 62 are used for inserting screws which fix the substrate 62 to a base of an illumination device.
- the through-holes 120 are arranged at intervals in a longitudinal direction of the substrate 62.
- a depressed part 105 on a first surface 65a of the substrate 62 has a plurality of curved parts 106 in positions corresponding to the through-holes 120.
- the curved parts 106 are curved in an arc shape in a direction going away from the end edge of the substrate 62, to detour around the through-holes 120.
- an insulating distance from the through-holes 120 to the depressed part 105 can be secured, by presence of the curved parts 106. Therefore, the dielectric strength of the substrate 62 is improved, and it is possible to sufficiently secure insulation of the screws from pads 72, even when the screws inserted through the through-holes 120 are formed of metal.
- FIG. 20 to FIG. 24 disclose a fifth embodiment.
- the fifth embodiment is different from the third embodiment, mainly in the shape of the second conductor pattern and the structure for cutting off electrical connection between pads obtained by the second conductor pattern.
- the basic structure of the substrate of the fifth embodiment other than these points is the same as that of the third embodiment. Therefore, in the fifth embodiment, constituent elements which are the same as those in the third embodiment are denoted by the same respective reference numerals as those of the third embodiment, and explanation thereof is omitted.
- a first conductor pattern 70 formed on a first surface 65a of a substrate 62 includes fourteen pads 72.
- the pads 72 are arranged in line at intervals in a longitudinal direction of the substrate 62.
- the fourteen pads 72 are electrically connected by a second conductor pattern 200 and maintained at the same potential, before the pads 72 are subjected to electroplating.
- the second conductor pattern 200 is formed on the first surface 65a of the substrate 62.
- the second conductor pattern 200 has a relay line 201, and a plurality of connection lines 202. As illustrated in FIG. 20 and FIG. 22 , the relay line 201 is positioned at the left end of the substrate 62, and extends along a short side 62c of the substrate 62.
- the relay line 201 electrically connects the pad 72 located at the left end of the substrate 62 with the first conductor pattern 70.
- connection lines 202 are drawn from the pads 72 and a power supply pattern 84a positioned at the right end of the substrate 62, and arranged between the pads 72 and a long side 62a of the substrate 62. End parts of each connection line 202 located at the end reverse to the pad 72 is guided toward the long side 62a of the substrate 62.
- the end parts of the connection lines 202 are assigned to removal positions P1, P2, P3 and P4 which are set in four positions of the long side 62a of the substrate 62.
- the removal positions P1, P2, P3 and P4 are arranged at intervals in the longitudinal direction of the substrate 62.
- the end parts of the four connection lines 202 which correspond to the first pad 72, located at the left end of the substrate 62, to the fourth pad 72 are guided to removal position P1 and collected therein.
- the end parts of the four connection lines 202 which correspond to the fifth pad 72 to the eighth pad 72 are guided to removal position P2 and collected therein.
- the end parts of the four connection lines 202 which correspond to the ninth pad 72 to the twelfth pad 72 are guided to removal position P3 and collected therein.
- the end parts of the two connection lines 202 which correspond to the thirteenth pad 72 to the fourteenth pad 72, and the end part of the connection line 202 which corresponds to the power supply pattern 84a are guided to removal position P4 and collected therein.
- the end parts of the connection lines 202 guided to each of the removal positions P1, P2, P3 and P4 are electrically connected to each other.
- a thermally radiative sheet 203 is deposited on a second surface 65b of the substrate 62.
- the thermally radiative sheet 203 is an example of a conductor, and formed of metal material which has excellent heat conductance such as copper foil.
- the thermally radiative sheet 203 covers the whole of the second surface 65b of the substrate 62.
- the second conductor pattern 200 becomes redundant after the pads 72 are subjected to electroplating. Therefore, in the fifth embodiment, after the pads 72 are subjected to electroplating, electrical connection between the pads 72 obtained by the second conductor pattern 200 is severed.
- a depressed part 204 which is traces of scraping away the parts of the substrate 62 is formed in the substrate 62.
- the depressed part 204 includes first to fifth cutoff parts 204a, 204b, 204c, 204d, and 204e.
- the first cutoff part 204a is formed in the short side 62c of the substrate 62.
- the second to fifth cutoff parts 204b, 204c, 204d, and 204e are formed in four positions of the long side 62a of the substrate 62.
- Each of the first to fifth cutoff parts 204a, 204b, 204c, 204d, and 204e has a bottom surface 205a and an internal periphery surface 205b, and is opened to the first surface 65a and the outer peripheral surface 65c of the substrate 62.
- the bottom surface 205a connects to the outer peripheral surface 65c of the substrate 62. Therefore, the first to fifth cutoff parts 204a, 204b, 204c, 204d, and 204e do not pierce through the substrate 62 in the thickness direction, and are positioned in corner parts defined by the first surface 65a and the outer peripheral surface 65c of the substrate 62.
- a creepage distance between the first conductor pattern 70 on the first surface 65a of the substrate 62 and the thermally radiative sheet 203 deposited on the second surface 65b of the substrate 62 is a value, which is obtained by adding the length of the bottom surface 204a of the depressed part 204.
- the creepage distance is longer than clearance between the first conductor pattern 70 on the first surface 65a of the substrate 62 and the thermally radiative sheet 203 deposited on the second surface 65b by the length of the bottom surface 204a of the recessed part 204.
- an insulation distance between the first conductor pattern 70 and the thermally radiative sheet 203 can be sufficiently secured, and the dielectric strength of the substrate 62 is improved.
- three through-holes 206 are formed in the center part of the substrate 62.
- the through-holes 206 are used for inserting screws, which fix the substrate 62 to a base of an illumination device, and arranged at intervals in the longitudinal direction of the substrate 62.
- electrical connection between all the pads 72 can be removed, by scraping away the four parts of the long side 62a of the substrate 62 and a part of the short side 62c of the substrate 62. Therefore, the range of the part which is scraped away from the substrate 62 is remarkably reduced, in comparison with the first embodiment and the third embodiment. As a result, the work of removing the second conductor pattern 71 can be easily performed in a short time, and the manufacturing cost of the substrate 62 can be reduced.
- the quantity of grinding swarf which is generated when the substrate 62 is scraped is reduced. This reduces the possibility that grinding swarf adheres to the pads 72, and prevents deterioration in the workability when the light-emitting elements are affixed to the pads 72.
- the light-emitting diode chips are mounted on the pads by the chip-on-board method.
- a light-emitting diode package obtained by combining a plurality of light-emitting diode chips may be mounted on the pads by the surface-mount method.
- the pads are preferably used as a power supply wiring pattern, they are not limited to use as wiring pattern. Specifically, when a reflecting layer is formed on the pads, the electrical-conduction function of the pads is not indispensable, and there are cases where the pads have only to exhibit a function of reflecting light emitted by the light-emitting elements, or a function as heat spreader which spreads heat generated by the light-emitting elements.
- the sealing members contain fluorescent material.
- the red light, green light, or blue light emitted by the light-emitting elements may be directly radiated to the outside of the light-emitting device.
- the illumination device using the light-emitting devices is applicable to light-source devices of an electric light bulb type, illumination tools used indoors or outdoors such as spotlights, and displays.
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- Condensed Matter Physics & Semiconductors (AREA)
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Abstract
Description
- Embodiments described herein relate generally to a light-emitting device using a light-emitting element such as light-emitting diode, a method of manufacturing the light-emitting device, and an illumination device to which the light-emitting device is mounted.
- In recent years, illumination devices using a plurality of light-emitting diodes as light source have been put into practical use. The illumination devices of this type are used as, for example, surface-mounted general lighting which is directly mounted on the indoor ceiling. For example, a conventional illumination device disclosed in Jpn. Pat. Appln. KOKAI Pub. No.
2009-54989 - On the other hand, in light-emitting devices using light-emitting diodes as light source, it is desired to efficiently take light emitted by the light-emitting diodes out of the light-emitting device. To satisfy the demand, known is a conventional light-emitting device having a structure in which a plurality of pads, on which light-emitting diodes are mounted, are provided on the substrate, and surfaces of the pads are covered with a light-reflecting layer. The light-reflecting layer is formed on the surfaces of the pads by subjecting the pads to electroplating.
- Electroplating has advantages of good close contact of metal coating with product to be treated, and inexpensive manufacturing cost. In the light-emitting device, however, since a plurality of pads are arranged at intervals on the substrate, when the pads are subjected to electroplating, it is necessary to electrically connect the pads by a dedicated conductor pattern, and maintain all the pads at the same potential.
- In addition, the conductor pattern becomes redundant after electroplating is finished. Therefore, it is necessary to perform work in which the conductor pattern is removed from the substrate by boring a number of holes in the substrate along the conductor pattern, and electrical connection between the pads by the conductor pattern is severed. The work of boring holes in the substrate has a large number of steps, and requires much time and labor. This decreases productivity and increases the cost of producing the light-emitting device.
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FIG. 1 is a plan view of a light-emitting device according to a first embodiment; -
FIG. 2 is a cross-sectional view taken along line F2-F2 ofFIG. 1 ; -
FIG. 3 is a plan view of a substrate which has a first conductor pattern including a plurality of pads, and a second conductor pattern, in the first embodiment; -
FIG. 4 is a cross-sectional view taken along line F4-F4 ofFIG. 3 ; -
FIG. 5 is a plan view of the substrate in a state where a common line of the second conductor pattern is removed, in the first embodiment; -
FIG. 6 is a cross-sectional view taken along line F6-F6 ofFIG. 5 ; -
FIG. 7 is a plan view of the substrate in a state where light-emitting elements are mounted on the pads of the first conductor pattern and the light-emitting elements are covered with a sealing member, in the first embodiment; -
FIG. 8 is a cross-sectional view of the light-emitting device, illustrating a state where a protective cover is separated from the substrate, in the first embodiment; -
FIG. 9 is a side view of an illumination device in which a pair of the light-emitting devices is fixed to a base, in the first embodiment; -
FIG. 10 is a plan view of the illumination device according to the first embodiment; -
FIG. 11 is a perspective view of an illumination device according to a second embodiment; -
FIG. 12 is a plan view of a light-emitting device according to a third embodiment; -
FIG. 13 is a plan view of a substrate which has a first conductor pattern including a plurality of pads, and a second conductor pattern, in the third embodiment; -
FIG. 14 is a plan view of the substrate, illustrating a state where a common line of the second conductor pattern is removed and a plurality of light-emitting elements are mounted on the pads, in the third embodiment; -
FIG. 15 is a plan view of the substrate, illustrating a state where the common line of the second conductor pattern is removed and a sealing member is applied onto the pads on which the light-emitting elements are mounted, in the third embodiment; -
FIG. 16 is a plan view of the substrate, to which a thermally radiative sheet is affixed, in the third embodiment; -
FIG. 17 is a cross-sectional view taken along line F17-F17 ofFIG. 12 ; -
FIG. 18 is a circuit diagram, illustrating a state where the light-emitting elements are electrically connected, in the third embodiment; -
FIG. 19 is a plan view of a light-emitting device according to a fourth embodiment; -
FIG. 20 is a plan view of a substrate used for a light-emitting device of a fifth embodiment; -
FIG. 21 is a plan view of the substrate, illustrating a state where electrical connection of pads is severed by a second conductor pattern, in the fifth embodiment; -
FIG. 22 is a plan view of the substrate, illustrating a part F22 ofFIG. 20 in an enlarged state; -
FIG. 23 is a plan view of the substrate, illustrating a part F23 ofFIG. 21 in an enlarged state; and -
FIG. 24 is a cross-sectional view taken along line F24-F24 ofFIG. 23 . - In general, according to one embodiment, a light-emitting device comprises a substrate, a plurality of pads, and a plurality of light-emitting elements. The pads have conductivity, and are arranged on the substrate. A reflecting layer formed by electroplating is provided on surfaces of the pads. The light-emitting elements are mounted on the respective pads. A depressed part remains on the substrate. The depressed part is formed in the substrate by removing a pattern on the substrate, which is electrically connected with the pads.
- The substrate is preferably formed of material which has thermal conductivity lower than that of metal. However, it is possible to use a substrate having a core material formed of metal which has excellent thermal conductivity such as aluminum. In addition, although the pads are preferably used as wiring pattern which supplies electric current to the light-emitting elements, the pads are not limited to being used as wiring pattern. Specifically, there are cases where it is sufficient that the pads have a function of reflecting light emitted by the light-emitting devices, or a function as heat spreader which spreads heat generated by the light-emitting elements.
- As the light-emitting elements, it is possible to use semiconductor light-emitting elements such as light-emitting diode chips. The light-emitting elements can be mounted on the substrate by, for example, the chip-on-board method or surface mount method. However, the method of mounting the light-emitting elements on the substrate is not specifically limited. In addition, the specific number of light-emitting elements and pads is not specifically limited.
- The pattern which is removed from the substrate is used for maintaining all the pads at the same potential when the pads are subjected to electroplating. In addition, the depressed part is a mark left on the substrate after the pattern is removed from the substrate, and the shape and the size of the depressed part are not specifically limited.
- A first embodiment will be described hereinafter with reference to
FIG. 1 to FIG. 10 . -
FIG. 1 to FIG. 8 illustrate a light-emittingdevice 1 which serves as illumination light source. As illustrated inFIG. 1 andFIG. 2 , the light-emittingdevice 1 comprises asubstrate 2, a plurality of light-emittingelements 3, a plurality of sealingmembers 4, and aprotective cover 5. - The
substrate 2 is formed of synthetic resin material, such as glass epoxy resin, which has thermal conductivity lower than that of metal. The material of thesubstrate 2 is not limited to glass epoxy resin, by other synthetic resin materials or ceramics materials can be used for thesubstrate 2. Although thesubstrate 2 is preferably formed of material which has thermal conductivity lower than that of metal, it is possible to adopt a substrate which has a core material formed of metal having excellent thermal conductivity such as aluminum. - As illustrated in
FIG. 1 andFIG. 2 , thesubstrate 2 has an elongated shape which has a pair oflong sides short sides substrate 2 has afirst surface 6a, and asecond surface 6b positioned opposite to thefirst surface 6a. The first and thesecond surfaces - As illustrated in
FIG. 3 and4 , afirst conductor pattern 7 and a second conductor pattern B are formed on thefirst surface 6a of thesubstrate 2. Thefirst conductor pattern 7 have a plurality ofpads 9 and anpower supply conductor 10. Eachpad 9 has an almost pentagonal shape in which one end is pointed. In the first embodiment, thepads 9 are arranged in 12 columns at intervals in the longitudinal direction of thesubstrate 2, and arranged in 4 rows at intervals in a direction perpendicular to the longitudinal direction of thesubstrate 2. - Therefore, forty-eight
pads 9 are regularly arranged in rows and columns on thefirst surface 6a of thesubstrate 2. In other words, the forty-eightpads 9 form twelvepad columns 13 which are arranged at intervals in the longitudinal direction of thesubstrate 2. Eachpad column 13 has fourpads 9 arranged in the direction perpendicular to the longitudinal direction of thesubstrate 2. - In addition, the
pad columns 13 are divided into sixpad columns 13 which are positioned on the right side of acenter line 01, which runs through the center of the longitudinal direction of thesubstrate 2, and sixpad columns 13 which are positioned on the left side of thecenter line 01. Thepad columns 13 positioned on the right side of thecenter line 01 and thepad columns 13 positioned on the left side of thecenter line 01 are arranged symmetrically with respect to thecenter line 01. - As illustrated in
FIG. 3 , in eachpad column 13, each of threepads 9 other than onepad 9 adjacent to thelong side 2a of thesubstrate 2 has awire connecting part 14. Eachwire connecting part 14 has a straight-line shape, and extends from an edge of thepad 9 in the direction perpendicular to the longitudinal direction of thesubstrate 2. A distal end of thewire connecting part 14 is positioned directly before theadjacent pad 9. - The
power supply conductor 10 includes a plurality of firstpower supply patterns 15, a secondpower supply pattern 16 which has acathode terminal 11a and a thirdpower supply pattern 17 which has ananode terminal 11b. Each of the firstpower supply patterns 15 is arranged betweenadjacent pad columns 13. The secondpower supply pattern 16 extends along thelong side 2b of thesubstrate 2, in the center part of thesubstrate 2 along the longitudinal direction of thesubstrate 2. The thirdpower supply pattern 17 extends over the whole length of thesubstrate 2 to run along thelong side 2a of thesubstrate 2, and connects twopad columns 13 which are arranged at both ends of the longitudinal direction of thesubstrate 2. Thecathode terminal 11a and theanode terminal 11b are positioned on thecenter line 01 of thesubstrate 2. Thecathode terminal 11a and theanode terminal 11b are electrically connected to a power supply circuit through lead lines. - As illustrated in
FIG. 2 , thefirst conductor pattern 7 including thepads 9 has a three-layer structure including acopper layer 20, anickel plating layer 21, and asilver plating layer 22. Thecopper layer 20 is formed by etching a copper foil deposited on thefirst surface 6a of thesubstrate 2. Thenickel plating layer 21 is formed on thecopper layer 20, by subjecting thecopper layer 20 to electroplating. Thesilver plating layer 22 is formed on thenickel plating layer 21, by subjecting thenickel plating layer 21 to electroplating. Thesilver plating layer 22 covers thenickel plating layer 21, and forms a reflecting layer exposed on the surface of thefirst conductor pattern 7. Therefore, the surface of thefirst conductor pattern 7 is a light-reflecting surface. The total light reflectance of the light-reflecting surface is, for example, 90%. - The
second conductor pattern 8 is used for maintaining all thepads 9 at the same potential, when thepads 9 of thefirst conductor pattern 7 are subjected to electroplating. Specifically, thesecond conductor pattern 8 has acommon line 24 and a plurality ofbranch lines 25. Thecommon line 24 extends in a straight line over the whole length of thesubstrate 2 to run along thelong side 2b of thesubstrate 2. In addition, thecommon line 24 is distant from an end edge of thesubstrate 2, which defines thelong side 2b of thesubstrate 2, by a predetermined distance D. Although thecommon line 24 is preferably formed in a straight-line shape, but may be formed in, for example, an arc shape or a meandering shape. - The
branch lines 25 are branched from thecommon line 24, and extend in a straight line toward spaces betweenadjacent pad columns 13. Distal ends of thebranch lines 25 are connected to therespective pads 9 of thepad columns 13. Therefore, all thepads 9 are electrically connected to thecommon line 24 through the branch lines 25. - The
second conductor pattern 8 is formed on thefirst surface 6a of thesubstrate 2 simultaneously with thefirst conductor pattern 7, and has a three-layer structure similar to that of thefirst conductor pattern 7. Specifically, as illustrated inFIG. 4 , thesecond conductor pattern 8 includes thecopper layer 20, thenickel plating layer 21, and thesilver plating layer 22. Thesilver plating layer 22 is exposed on the surface of thesecond conductor pattern 8. Therefore, the surface of thesecond conductor pattern 8 is also a light-reflecting surface. - In the first embodiment, light-emitting diode chips are used as the light-emitting
elements 3. The light-emitting diode chips are, for example, InGaN-based elements, and includes sapphire board which has light transmittance, and a light-emitting layer which is deposited on the sapphire board and emits blue light. The light-emitting layer is formed by depositing an N-type nitride semiconductor layer, an InGaN light-emitting layer, and a P-type nitride semiconductor layer each other. - In addition, each of the light-emitting diode chips includes a positive electrode and a negative electrode, which supply electric current to the light-emitting layer. The positive electrode has a P-type electrode pad which is formed on the P-type nitride semiconductor layer. The negative electrode has an N-type electrode pad which is formed on the N-type nitride semiconductor layer.
- The light-emitting
elements 3 are individually mounted on thesilver plating layer 22 serving as the surfaces of therespective pads 9, by using an adhesive 26 formed of silicone resin. Therefore, in the first embodiment, forty-eight light-emittingelements 3 are regularly arranged in rows and columns on thefirst surface 6a of thesubstrate 2. The light-emittingelements 3 are smaller in shape than thepads 9. Therefore, the light-reflectingpads 9 project around the light-emittingelements 3 on thefirst surface 6a of thesubstrate 2. - As illustrated in
FIG. 2 , the positive electrode of each light-emittingelement 3 is electrically connected to thepad 9, to which the light-emittingelement 3 is affixed, through abonding wire 28. The negative electrode of each light-emittingelement 3 is electrically connected to thewire connecting part 14 of theadjacent pad 9, through anotherbonding wire 29. - As illustrated in
FIG. 7 , in each of the twopad columns 13 which are adjacent to each other with thecenter line 01 of thesubstrate 2 interposed therebetween, the negative electrode of the light-emittingelement 3 which is affixed to thepad 9 adjacent to thelong side 2b of thesubstrate 2 is electrically connected to the secondpower supply pattern 16 through thebonding wire 29. - In each of the
other pad columns 13, the negative electrode of the light-emittingelement 3 which is affixed to thepad 9 adjacent to thelong side 2b of thesubstrate 2 is electrically connected to the firstpower supply pattern 15 through thebonding wire 29. - As a result, the light-emitting
elements 3 are connected in series in eachpad column 13, and form twelve light-emitting element columns which correspond to the pad columns. The twelve light-emitting element columns are connected in parallel with the secondpower supply pattern 16 and the thirdpower supply pattern 17. - In the first embodiment, gold wires are used as the
bonding wires bonding wires elements 3 through bumps mainly formed of gold (Au), to improve the mounting strength of thebonding wires elements 3. - The
second conductor pattern 8, which maintains all thepads 9 of thefirst conductor pattern 7 at the same potential, is redundant after thepads 9 are subjected to electroplating. Therefore, in the first embodiment, after thepads 9 are subjected to electroplating, thecommon line 24 of thesecond conductor pattern 8 is removed, to sever electrical connection between thepads 9 by thesecond conductor pattern 8. - As a result, as illustrated in
FIG. 5 to FIG. 7 , a groove-likedepressed part 33 is formed in thefirst surface 6a. Thedepressed part 33 is a trace which is left after thecommon line 24 is removed, and extends in a straight line along thelong side 2b of thesubstrate 2. Thedepressed part 33 is positioned between the end edge of thesubstrate 2 which defines thelong side 2b of thesubstrate 2 and the firstpower supply patterns 15 on thesubstrate 2, and is distant from the end edge of thesubstrate 2 by the predetermined distance. Thedepressed part 33 is defined by abottom surface 33a and a pair of side surfaces 33b and 33c, and opened to thefirst surface 6a of thesubstrate 2. InFIG. 1 ,FIG. 5 andFIG. 7 , thedepressed part 33 is painted with black color to clearly distinguish thedepressed part 33 from thesecond conductor pattern 8. - By presence of the
depressed part 33, only thebranch lines 25 of thesecond conductor pattern 8 are left on thefirst surface 6a of thesubstrate 2. In addition, a creepage distance between the end edge of thesubstrate 2 which defines thelong side 2b of thesubstrate 2 and the firstpower supply patterns 15 on thesubstrate 2 is a value obtained by adding the height of the side surfaces 33b and 33c of thedepressed part 33. Therefore, the creepage distance is longer than the clearance between the end edge of thesubstrate 2 and thefirst conductor pattern 7 by the depth of thedepressed part 33. - The shape of the
depressed part 33 is not limited to the first embodiment. For example, thedepressed part 33 may have a V-shaped or U-shaped cross section in the direction perpendicular to the longitudinal direction of thesubstrate 2. - The sealing
members 4 are elements for sealing the individual light-emittingelements 3 and thebonding wires elements 3 on thepads 9, and rise in a hemispherical shape from therespective pads 9. For example, transparent silicone resin having light transmittance is used as the sealingmembers 4. The silicone resin is applied in a liquid state onto eachpad 9. The applied silicone resin is cured by heating or natural drying, and held on eachpad 9. - The sealing
member 4 contains fluorescent material. The fluorescent material is uniformly dispersed in thesealing members 4. As the fluorescent material, used is yellow fluorescent material which is excited by blue light emitted by the light-emittingelements 3 and emits yellow light. The fluorescent material mixed into the sealingmembers 4 is not limited to yellow fluorescent material. For example, to improve the color rendering properties of light emitted by the light-emittingelements 3, it is possible to add red fluorescent material which is excited by blue light and emits red light, or green fluorescent material which emits green light, to thesealing members 4. - As illustrated in
FIG. 2 , theprotective cover 5 covers thesubstrate 2 on which the light-emittingelements 3 are sealed. Theprotective cover 5 is formed of synthetic resin material having light transmittance, such as transparent acrylic resin and polycarbonate resin. Theprotective cover 5 includes areceptacle 35 into which thesubstrate 2 is fitted. Thereceptacle 35 has abottom surface 35a which is opposed to thefirst surface 6a of thesubstrate 2, and anopening end 35b which is opposed to thebottom surface 35a. The openingend 35b of thereceptacle 35 is opened to aback surface 5a of theprotective cover 5. - A plurality of
depressions 36 are formed in thebottom surface 35a of thereceptacle 35. Thedepressions 36 are arranged in rows and columns on thebottom surface 35a to correspond to the respective light-emittingelements 3. Thedepressions 36 have a conic shape which has a circular opening part opened to thebottom surface 35a, and are opposed to therespective sealing members 4 covering the light-emittingelements 3. The spherical top parts of the sealingmembers 4 get into therespective depressions 36 through the opening parts of thedepressions 36. - In addition, the
protective cover 5 has aflange part 37. Theflange part 37 surrounds the openingend 35b of thereceptacle 35, and projects from the outer peripheral surface of theprotective cover 5 to the outside of theprotective cover 5. - As illustrated in
FIG. 2 , thesubstrate 2 is fixed within thereceptacle 35 of theprotective cover 5, by transparent silicone-resin-basedadhesive 38. The adhesive 38 is filled into a space between thefirst surface 6a of thesubstrate 2 and thebottom surface 35a of thereceptacle 35. In the state where thesubstrate 2 is fixed within thereceptacle 35 of theprotective cover 5, the opening parts of thedepressions 36 are closed with the sealingmembers 4 and the adhesive 38. As a result, the inside parts of thedepressions 36 become closed spaces, and anair layer 39 is formed between theprotective cover 5 and the sealingmembers 4. In addition, in the state where thesubstrate 2 is fixed within thereceptacle 35 of theprotective cover 5, thesecond surface 6b of thesubstrate 2 is positioned inside thereceptacle 35 more than theback surface 5a of theprotective cover 5 does. - Next, a process of manufacturing the light-emitting
device 1 is explained with reference toFIG. 3 to FIG. 8 . - First, the
first conductor pattern 7 and thesecond conductor pattern 8 are formed on thefirst surface 6a of thesubstrate 2. Specifically, the foil deposited on thefirst surface 6a is etched, and thereby acopper layer 20 of thefirst conductor pattern 7 and acopper layer 20 of thesecond conductor pattern 8 are formed. Among thecopper layer 20 of thefirst conductor pattern 7, parts which form thepads 9 are electrically connected to each other through thecopper layer 20 of thesecond conductor pattern 8. Therefore, all the parts of thecopper layer 20 of thefirst conductor pattern 7, which form thepads 9, are maintained at the same potential. - In this state, the copper layers 20 of the first and the
second conductor patterns nickel plating layer 21 is formed on the copper layers. Thereafter, thenickel plating layer 21 is subjected to electroplating, and thereby asilver plating layer 22 is formed on thenickel plating layer 21. In the step of performing electroplating, all the parts which form thepads 9 in thecopper layer 20 of thefirst conductor pattern 7 are maintained at the same potential. Therefore, thenickel plating layer 21 and thesilver plating layer 22 are formed on thecopper layer 20 of thefirst conductor pattern 7, by using thecopper layer 20 of thefirst conductor pattern 7 as cathode, using the same metal as plating layer as anode, and causing an electric current to flow between the cathode and the anode. Thenickel plating layer 21 and thesilver plating layer 22 are also formed on thecopper layer 20 of thesecond conductor pattern 8 simultaneously with thefirst conductor pattern 7. - Thereafter, as illustrated in
FIG. 5 andFIG. 6 , thecommon line 24 of thesecond conductor pattern 8 is removed from thefirst surface 6a of thesubstrate 2. Specifically, thecommon line 24 on thefirst surface 6a is scraped away by using an electrical tool such as a router and a trimmer. As a result, electrical connection between thepads 9 of thefirst conductor pattern 7 and thecommon line 24 is severed, and thepads 9 become electrically independent. - Simultaneously with scraping away the
common line 24 from thefirst surface 6a, a groove-likedepressed part 33 is formed in thefirst surface 6a. Thedepressed part 33 crosses over the bases of thebranch lines 25 branching off from thecommon line 24. As a result, thebranch lines 25 are left on thefirst surface 6a of thesubstrate 2, in a state of being electrically separated from each other. - Thereafter, light-emitting
elements 3 are affixed on therespective pads 9 of thefirst conductor pattern 7. Then, the positive electrode of each light-emittingelement 3 is electrically connected to thepad 9, to which the light-emittingelement 3 is affixed, by bondingwire 28. In the same manner, the negative electrode of each light-emittingelement 3 is connected to thewire connecting part 14 of theadjacent pad 9 and the firstpower supply pattern 15 bybonding wire 29. - Then, sealing
members 4 are individually applied onto therespective pads 9 to which the light-emittingelements 3 are affixed, to cover the light-emittingelements 3 and thebonding wires elements 3 with the sealingmembers 4. Thereafter, the applied sealingmembers 4 are cured. Thereby, the light-emittingelements 3 and thebonding wires first surface 6a of thesubstrate 2 by the sealing members 4'. - Next, as illustrated in
FIG. 8 , theprotective cover 5 is held in a position in which thebottom surface 33a of thereceptacle 35 of theprotective cover 5 faces upward. In this state, silicone-basedadhesive 38 is applied to thebottom surface 33a of thereceptacle 35. Then, thesubstrate 2 on which the light-emittingelements 3 are sealed is deposited in thereceptacle 35 of theprotective cover 5, and thehemispherical sealing members 4 covering the light-emittingelements 3 are positioned in the opening parts of thedepressions 36. - As a result, the
first surface 6a of thesubstrate 2 is affixed to thebottom surface 35a of thereceptacle 35 by the silicone-basedadhesive 38, and thesubstrate 2 is united with theprotective cover 5. Thereby, a series of manufacturing steps of the light-emittingdevice 1 is finished. - Next, an
illumination device 41 which uses the light-emittingdevice 1 as light source will be explained hereinafter, with reference toFIG. 9 and10 in addition to the above drawings. Theillumination device 41 is used by directly attaching theillumination device 41 to, for example, the indoor ceiling C. Theillumination device 41 comprises abase 42, and two light-emittingdevices 1. Thebase 42 is an example of a main body of theillumination device 41, and formed in a rectangular shape by using metal material such as aluminum. Thebase 42 is fixed to the ceiling C by bolts. - The two light-emitting
devices 1 are arranged in a straight line along a longitudinal direction of thebase 42, and are electrically connected to a power supply unit (not shown) including a power supply circuit. Each light-emittingdevice 1 is fixed to thebase 2 by a plurality ofscrews 43. Thescrews 43 are screwed into thebase 2 through theflange part 37 of theprotective cover 5. Therefore, theprotective cover 5 also functions as bracket to fix the light-emittingdevices 1 to thebase 42. - In a state where the light-emitting
devices 1 are fixed to thebase 42, theback surface 5a of theprotective cover 5 contacts thebase 42, and the openingend 35b of thereceptacle 35 is closed by thebase 42. Thesecond surface 6b of thesubstrate 2, which is received into thereceptacle 35 goes inside thereceptacle 35 more than theback surface 5a of theprotective cover 5 does, as illustrated inFIG. 2 . Therefore, thesecond surface 6b of thesubstrate 2 is distant from thebase 42. A space between thesubstrate 2 and the base 42 functions as a thermal insulatinglayer 44. The thermal insulatinglayer 44 is not limited to the space. For example, a thermal insulating material may be filled into the space between thesubstrate 2 and thebase 42. - In the
illumination device 41 having the above structure, a voltage is applied to the two light-emittingdevices 1 through the power supply unit. As a result, the light-emittingelements 3 on thesubstrate 2 emit light all together. The blue light emitted by the light-emittingelements 3 is made incident on the sealingmembers 4. Part of the blue light made incident on the sealingmembers 4 is absorbed into the yellow fluorescent material. The rest of the blue light passes through the sealingmembers 4, without being absorbed into the yellow fluorescent material. - The yellow fluorescent material which has absorbed the blue light is excited and emits yellow light. Since yellow light passes through the sealing
members 4, the yellow light and the blue light are mixed each other inside the sealingmembers 4, and become white light. The white light passes through theprotective cover 5 through theair layer 39, and is guided to the outside of the light-emittingdevice 1. As a result, the light-emittingdevice 1 serves as a surface light source which emits white light. The white light emitted by the light-emittingdevice 1 is used for illuminating the inside of the room from the ceiling. - When the light-emitting
devices 1 emit light, heat generated by the light-emittingelements 3 is individually conducted to thepads 9 on thesubstrate 2. Thepads 9 functions as heat spreader which spreads heat conducted from the light-emittingelements 3. The heat which is spread by thepads 9 is mainly conducted from thepads 9 to theprotective cover 5, and radiated from theprotective cover 5 to the outside of the light-emittingdevices 1. Therefore, thermal transmission from thesecond surface 6b of thesubstrate 2 to thebase 42 of theillumination device 41 is suppressed, and the heat of the light-emittingelements 3 is not easily conducted to the ceiling C. - In the first embodiment, the
substrate 2 is formed of synthetic resin material which has thermal conductance lower than that of metal. In addition, the thermal insulatinglayer 44 is interposed between thesubstrate 2 and thebase 42. As a result, thermal transmission from thesubstrate 2 to thebase 42 is suppressed, and thermal transmission from thesubstrate 2 to theprotective cover 5 is promoted. Therefore, the heat of the light-emittingelements 3 can be positively radiated from theprotective cover 5. - According to the first embodiment, the
pads 9, to which the light-emittingelements 3 are affixed, project around the light-emittingelements 3. In addition, thepads 9 have light reflectance by virtue of presence of thesilver plating layer 22. Therefore, most of light going from the light-emittingelements 9 toward thesubstrate 2 is reflected by thesilver plating layer 22, and guided to a direction in which the light is to be taken out. Thus, the light emitted by the light-emittingelements 3 can be efficiently taken out of the light-emittingdevices 1. - In addition, the
depressions 36 of theprotective cover 5 form theair layer 39 between the sealingmembers 4 covering the light-emittingelements 3 and theprotective cover 5. The light of the light-emittingelements 3 which is transmitted through the sealingmembers 4 is diffused when it passes through the interface between theair layer 39 and theprotective cover 5. The diffused light is transmitted through theprotective cover 5, and radiated to the outside of the light-emittingdevice 1. Therefore, the luminance of the surface of theprotective cover 5 is made uniform, and the light-emittingdevice 1 has good appearance while the light-emittingdevice 1 is lit. - In addition, the light-emitting
device 1 includes the light-transmittingprotective cover 5 which covers thesubstrate 2 and the light-emittingelements 3. Therefore, when the light-emittingdevice 1 is used as light source of theillumination device 41, it is possible to eliminate a shade and a globe from theillumination device 41. This enables simplifying the structure of theillumination device 41. - The
substrate 2 to which the light-emittingelements 3 are affixed is contained in thereceptacle 35 of theprotective cover 5, and affixed to thebottom surface 35a of thereceptacle 35 by the adhesive 38. The adhesive 38 is filled into the space between thebottom surface 35a of thereceptacle 35 and thesubstrate 2, and surrounds the sealingmembers 4. This structure prevents dust and water from infiltrating the space between thesubstrate 2 and theprotective cover 5. Therefore, the sealingmembers 4, through which the light of the light-emittingelements 3 is transmitted, are not easily soiled, and it is possible to add a waterproof function to theillumination device 41. - In addition, the sealing
members 4 are applied to thesubstrate 2, to individually cover the forty-eight light-emittingelements 3 and thebonding wires elements 3. Therefore, it is possible to reduce the quantity of the silicone resin and the fluorescent material added to the silicone resin, in comparison with the case where all the light-emittingelements 3 are continuously covered with silicone resin. This is advantageous for suppressing the cost of the light-emittingdevice 1. - On the other hand, the
second conductor pattern 8, which maintains all thepads 9 at the same potential when thepads 9 of thefirst conductor pattern 7 are subjected to electroplating, is formed of thecommon line 4 and a plurality ofbranch lines 25 which connect thecommon line 24 to thepads 9. - Therefore, electrical connection between the
pads 9 achieved by thesecond conductor pattern 8 can be severed by scraping off thecommon line 24 by an electrical tool or the like. In addition, since thecommon line 24 has a simple shape which extends in a straight line along thelong side 2b of thesubstrate 2, thecommon line 24 can be scraped off by simply moving the electrical tool in a straight line along thecommon line 24. Therefore, it is possible to efficiently and easily perform work of removing thecommon line 24 from thesubstrate 2, and improve the productivity of the light-emittingdevice 1. - In addition, the groove-like
depressed part 33 which is left after thecommon line 24 is scraped off is distant from the end edge of thesubstrate 2, which defines thelong side 2b of thesubstrate 2, by the predetermined distance, and is positioned between the end edge of thesubstrate 2 and the firstpower supply patterns 15 on thesubstrate 2. As a result, the creepage distance between the end edge of thesubstrate 2 and the firstpower supply patterns 15 becomes longer than the clearance between the end edge of thesubstrate 2 and the firstpower supply patterns 15, by a length corresponding to the depth of thedepressed part 33. Therefore, when an electrical-conductive element is positioned around thesubstrate 2, it is possible to secure an insulating distance between the electrical-conductive element and the firstpower supply patterns 15, and dielectric strength of thesubstrate 2 is improved. -
FIG. 11 discloses anillumination device 51 according to a second embodiment. - The
illumination device 51 uses three light-emittingdevices 1 as light source. The structure of the light-emittingdevice 1 is the same as that of the first embodiment. InFIG. 11 , a protective cover is omitted to show the internal structure of the light-emittingdevices 1. - As illustrated in
FIG. 11 , theillumination device 51 includes acase 52 which is surface-mounted on the ceiling. Thecase 52 is an example of a main body of theillumination device 51. Thecase 52 has an elongated box shape, and has an elongated openingpart 53 which is opened downward. The three light-emittingdevices 1 and a power supply unit which lights the three light-emittingdevices 1 are contained in thecase 52. The light-emittingdevices 1 are arranged in line along a longitudinal direction of thecase 52. The protective cover of each light-emittingdevice 1 is exposed from the openingpart 53 of thecase 52 to the outside of thecase 52. In other words, the protective cover of each light-emittingdevice 1 covers theopening part 53 of thecase 52 from the inside of thecase 52. Therefore, thecase 52 does not need a dedicated translucent cover which covers theopening part 53. - According to the second embodiment described above, it is possible to provide the
illumination device 51 which has the same effect as that of the first embodiment. -
FIG. 12 to FIG. 18 disclose a light-emittingdevice 61 according to a third embodiment. - The light-emitting
device 61 which serves as illumination light source comprises asubstrate 62, a plurality of light-emittingelements 63, and a pair of sealingmembers substrate 62 is formed of a synthetic resin material such as glass epoxy resin. Thesubstrate 62 has an elongated shape which has a pair oflong sides short sides substrate 62 has afirst surface 65a, asecond surface 65b positioned opposite to thefirst surface 65a, and an outerperipheral surface 65c which connects thefirst surface 65a with thesecond surface 65b. The first and thesecond surfaces substrate 62 along thelong sides substrate 62 along theshort sides substrate 62 is preferably 0.5 mm to 1.8 mm. In the second embodiment, thesubstrate 62 having a thickness of 1.0 mm is used. - A plurality of piercing
parts 66 are formed at end edges which define thelong sides substrate 62. The piercingparts 66 are arc-shaped cut-away portions which are opened to the outer peripheral surface 63c of thesubstrate 62, and pierce through thesubstrate 62 in a thickness direction. In addition, the piercingparts 66 are arranged at intervals in the longitudinal direction of thesubstrate 62. - A plurality of
screws 68 are inserted through the respective piercingparts 66. Thescrews 68 are an example of fixing parts which fix thesubstrate 62 to a base of the illumination device, and are screwed into the base through the piercingparts 66. In a state where thescrews 68 are screwed into the base, the end edge of thesubstrate 62 is held between head parts of thescrews 68 and the base. Thereby, thesubstrate 62 is fixed to the base. - As illustrated in
FIG. 13 , afirst conductor pattern 70 and asecond conductor pattern 71 are formed on thefirst surface 65a of thesubstrate 62. Thefirst conductor pattern 70 includes, for example, ninepads 72, a positivepower supply conductor 73, a negativepower supply conductor 74, and arelay conductor 75. Thepads 72 have a rectangular shape, and are arranged in line at intervals in the longitudinal direction of thesubstrate 62. - Each
pad 72 is divided into afirst mounting area 76a and asecond mounting area 76b by aslit 72a. Theslit 72a extends in the center part of thepad 72 in a straight line in the longitudinal direction of thesubstrate 62, and is opened to one end of thepad 72. Sixdepressed parts 77 are formed in the first mountingarea 76a of eachpad 72. Thedepressed parts 77 are opened to one side edge of thepad 72, and arranged in line at intervals in the longitudinal direction of thesubstrate 62. In the same manner, sixdepressed parts 77 are formed in thesecond mounting area 76b of eachpad 72. Thedepressed parts 77 are opened to theslit 72a, and arranged in line at intervals in the longitudinal direction of thesubstrate 62. - As illustrated in
FIG. 13 , each of thepads 72 other than onepad 72 positioned at the left end of thesubstrate 62 has a pair ofextension parts extension parts pad 72 in the longitudinal direction of thesubstrate 62, and are arranged in parallel with each other at an interval. Each of theextension parts power supply terminals 80. Thepower supply terminals 80 project from theextension parts substrate 62. - One
extension part 79a of eachpad 72 extends along one side edge of theadjacent pad 72. Thepower supply terminals 80 of theextension part 79a are inserted into the respectivedepressed parts 77 opened to one side edge of thepad 72. Theextension part 79a and the side edge of thepad 72 are electrically separated by providing an insulating space between them. In the same manner, thepower supply terminals 80 of theextension part 79a and thedepressed parts 77 are electrically separated by providing insulating spaces between them. - The
other extension part 79b of eachpad 72 is inserted into theslit 72a of theadjacent pad 72. Thepower supply terminals 80 of theextension part 79b are inserted into the respectivedepressed parts 77 opened to theslit 72a. Theextension part 79b and thepad 72 are electrically separated by providing an insulating space positioned inside theslit 72a. In the same manner, thepower supply terminals 80 of theextension part 79b and thedepressed parts 77 are electrically separated by providing insulating spaces between them. - Therefore, as is clear from
FIG. 13 , thepads 72 are arranged in line in the longitudinal direction of thesubstrate 62, in a state where theextension parts substrate 62. - As illustrated in
FIG. 13 , the positivepower supply conductor 73 extends over the whole length of thesubstrate 62 to run along thelong side 62b of thesubstrate 62. The negativepower supply conductor 74 extends along the longitudinal direction of thesubstrate 62 to run along thelong side 62b of thesubstrate 62. The left end of the negativepower supply conductor 74 is connected to thepad 72 positioned at the left end of thesubstrate 62. - The positive
power supply conductor 73 has ananode terminal 81. In the same manner, the negativepower supply conductor 74 has a cathode terminal B2. Theanode terminal 81 and thecathode terminal 82 are aligned at an interval in the left end part of thesubstrate 62. - The
relay conductor 75 extends along the longitudinal direction of thesubstrate 62 to run along thelong side 62b of thesubstrate 62. Therelay conductor 75 is positioned in a right end part of thesubstrate 62. Therelay conductor 75 includes a pair ofpower supply patterns power supply patterns substrate 62, and are arranged in parallel with each other with a space between them. Each of thepower supply patterns power supply terminals 85. Thepower supply terminals 85 project from thepower supply patterns substrate 62. - One
power supply pattern 84a extends along one side edge of thepad 72 positioned at the right end of thesubstrate 62. Thepower supply terminals 85 of thepower supply pattern 84a are inserted into the respectivedepressed parts 77 opened to the side edge of thepad 72. Thepower supply pattern 84a and the side edge of thepad 72 are electrically separated by providing an insulating space between them. In the same manner, thepower supply terminals 85 of thepower supply pattern 84a and thedepressed parts 77 of thepad 72 are electrically separated by providing insulating spaces between them. - The other
power supply pattern 84b is inserted into theslit 72a of thepad 72 positioned at the right end of thesubstrate 62. Thepower supply terminals 85 of thepower supply pattern 84b are inserted into the respectivedepressed parts 77 opened to theslit 72a. Thepower supply pattern 84b and thepad 72 are electrically separated by providing an insulating space between them. In the same manner, thepower supply terminals 85 of thepower supply pattern 84b and thedepressed parts 77 of thepad 72 are electrically separated by providing insulating spaces between them. - As illustrated in
FIG. 12 andFIG. 13 , apower supply connector 86 is soldered to theanode terminal 81 and thecathode terminal 82. Thepower supply connector 86 is positioned on thefirst surface 65a of thesubstrate 62, and electrically connected to the power supply circuit throughlead lines 86a. In addition, the negativepower supply conductor 74 and therelay conductor 85 are short-circuited through arelay connector 87. - As illustrated in
FIG. 17 , thefirst conductor pattern 70 including thepads 72 has a three-layer structure including acopper layer 88, anickel plating layer 89, and asilver plating layer 90. Thecopper layer 88 is formed by etching a copper foil deposited on thefirst surface 65a of thesubstrate 62. Thenickel plating layer 89 is formed on thecopper layer 88 by subjecting thecopper layer 88 to electroplating. Thesilver plating layer 90 is formed on thenickel plating layer 89 by subjecting thenickel plating layer 89 to electroplating. Thesilver plating layer 90 covers thenickel plating layer 89, and forms a reflecting layer which is exposed to the surface of thefirst conductor pattern 70. Therefore, the surface of thefirst conductor pattern 70 is a light-reflecting surface. - The
nickel plating layer 89 preferably has a thickness of 5 µm or more. In the same manner, thesilver plating layer 90 preferably has a thickness of 1 µm or more. Specifying the thicknesses of thenickel plating layer 89 and thesilver plating layer 90 like this solves the problem of variations in thicknesses of thenickel plating layer 89 and thesilver plating layer 90, and makes the light reflectance of all thepads 72 uniform. - The
second conductor pattern 71 is used for maintaining all thepads 72 at the same potential when thepads 72 of thefirst conductor pattern 70 to electroplating. Specifically, thesecond conductor pattern 71 includes acommon line 92 and a plurality ofbranch lines 93 as illustrated inFIG. 13 . Thecommon line 92 extends in a straight line over the whole length of thesubstrate 62 to run along thelong side 62a of thesubstrate 62. Simultaneously, thecommon line 92 is distant from the end edge of thesubstrate 62, which defines thelong side 62a of thesubstrate 62, by a predetermined distance D. - In addition, the
common line 92 has a plurality ofcurved parts 94 in positions corresponding to the piercingparts 66 of thesubstrate 62. Thecurved parts 94 are curved in arc shape in a direction going away from the edges of the piercingparts 66. By presence of thecurved parts 94, thecommon line 92 is distant from the edges of the piercingparts 66, by at least the same distance as the distance D in the parts corresponding to the piercingparts 66. - The
branch lines 93 are branched from thecommon line 92, and extend in a straight line toward thepads 72. Thebranch lines 93 are arranged at intervals in the longitudinal direction of thesubstrate 62. Distal ends of thebranch lines 93 are electrically connected to all thepads 72 and thepower supply pattern 84a of therelay conductor 75. In other words, all thepads 72 and therelay conductor 75 are electrically connected to thecommon line 92 through the branch lines 93. - The
second conductor pattern 71 is formed on thefirst surface 65a of thesubstrate 62 simultaneously with thefirst conductor pattern 70, and has the same three-layer structure as that of thefirst conductor pattern 70. Therefore, the surface of thesecond conductor pattern 71 is formed of a silver plating layer, and has light reflectance. - Each light-emitting
element 63 is a light-emitting diode chip as in the first embodiment, and has a positive electrode and a negative electrode. The light-emittingelements 63 are affixed to thefirst mounting areas 76a and the second mountingareas 76b of thepads 72 by a silicone-resin-basedadhesive 96. Specifically, six light-emittingelements 63 are arranged in the first mountingarea 76a of eachpad 72 in line at intervals in the longitudinal direction of thesubstrate 62, and six light-emittingelements 63 are arranged in thesecond mounting area 76b of eachpad 72 in line at intervals in the longitudinal direction of thesubstrate 62. Therefore, eachpad 72 includes twelve light-emittingelements 63. The light-emittingelements 63 on eachpad 72 form two rows of light-emitting elements which are successively arranged in the longitudinal direction of thesubstrate 62. - As illustrated in
FIG. 14 andFIG. 17 , the positive electrode of each light-emittingelement 63 is electrically connected to thepad 72, to which the light-emittingelement 63 is affixed, by abonding wire 98. The negative electrode of each light-emittingelement 63 is electrically connected to thepower supply terminals 80 of theadjacent pad 72 and thepower supply terminals 85 of thepower supply patterns bonding wire 99. Specifically, as illustrated inFIG. 18 , the light-emittingdevice 61 has nineparallel circuits elements 63 are connected in parallel. In addition, the nineparallel circuits - In addition, in the third embodiment, to prevent malfunction of the light-emitting
device 61, acapacitor 101 is connected to each of the nineparallel circuits capacitor 101 is also connected to a circuit which connects theparallel circuits capacitors 101 are mounted on thefirst surface 65a of thesubstrate 62. - In the third embodiment, the
power supply terminals bonding wire 99 is connected are inserted into thedepressed parts 77 of theadjacent pad 72. In other words, since thepower supply terminals second mounting areas elements 63 can be affixed to the center parts of the first and thesecond mounting areas bonding wires elements 63 to a wide range of the first and thesecond mounting areas pads 72. - The
second conductor pattern 71 which all thepads 72 at the same potential becomes redundant after thefirst conductor pattern 70 is subjected to electroplating. Therefore, in the third embodiment, after thefirst conductor pattern 70 is subjected to electroplating, thecommon line 92 of thesecond conductor pattern 71 is removed, to sever electrical connection between thepads 72 obtained by thesecond conductor pattern 71. - As illustrated in
FIG. 14 ,FIG. 15 andFIG. 17 , adepressed part 105 is formed in thefirst surface 65a of thesubstrate 62. Thedepressed part 105 is a trace which is left after thecommon line 92 is removed, and extends along thelong side 62a of thesubstrate 62. Thedepressed part 105 is a groove which is defined by abottom surface 105a and a pair of side surfaces 105b and 105c, and opened to thefirst surface 65a of thesubstrate 62. - In addition, the
depressed part 105 has a plurality ofcurved parts 106 in positions corresponding to the piercingparts 66 of thesubstrate 62. Thecurved parts 106 are formed in a shape which agrees with the shape of thecurved parts 94 of thecommon line 92, to detour around the piercingparts 66. Thedepressed part 105 having the above structure is positioned between the end edge of thesubstrate 62, which defines thelong side 62a of thesubstrate 62, and thepads 72, and distant from the end edge of thesubstrate 62 by a predetermined distance. According to the third embodiment, thedepressed part 105 has a width of 1 mm, and a depth of 0.3 mm. - By presence of the
depressed part 105 as described above, only thebranch lines 93 of thesecond conductor pattern 71 remain on thefirst surface 65a of thesubstrate 62. The remainingbranch patterns 93 are electrically separated. In addition, a creepage distance between the end edge of thesubstrate 62 which defines thelong side 62a of thesubstrate 62 and thepads 72 is a value obtained by adding the height of the side surfaces 105b and 105c of thedepressed part 105. Therefore, the creepage distance is longer than the clearance between the end edge of thesubstrate 62 and thepads 72 by the depth of thedepressed part 105. The shape of thedepressed part 105 is not limited to the third embodiment. For example, thedepressed part 105 may have a V-shaped or U-shaped cross section in the direction perpendicular to the longitudinal direction of thesubstrate 62. - The sealing
members elements 63, which are arranged in two lines, and thebonding wires pads 72. The sealingmembers substrate 62. - As illustrated in
FIG. 12 andFIG. 17 , thefirst surface 65a of thesubstrate 62 is covered with a white resistlayer 108, except for areas on which parts such as the light-emittingelements 63 and thecapacitors 101 are mounted. The resistlayer 108 has light reflectance. The resistlayer 108 continuously covers thefirst conductor pattern 70, thebranch lines 93, and thedepressed part 105. Therefore, thefirst conductor pattern 70, thebranch lines 93 and thedepressed part 105 on thefirst surface 65a of thesubstrate 62 are not easily viewed. - As illustrated in
FIG. 16 andFIG. 17 , eighteen rectangular thermallyradiative sheets 110 are deposited on thesecond surface 65b of thesubstrate 62. The thermallyradiative sheets 110 are an example of conductors, and are formed of a copper foil which has excellent heat conductance. The thermallyradiative sheets 110 are arranged in two lines at intervals in the longitudinal direction of thesubstrate 62, to correspond to thepads 72 of thefirst surface 65a. The adjacent thermallyradiative sheets 110 are thermally separated by a plurality offirst slits 111, which extend in the longitudinal direction of thesubstrate 62, and a plurality ofsecond slits 112 which extend in the direction perpendicular to the longitudinal direction of thesubstrate 62. In addition, the thermallyradiative sheets 110 and thesecond surface 65b of thesubstrate 62 is covered with a resistlayer 113. - By depositing the thermally
radiative sheets 110 on thesecond surface 65b of thesubstrate 62, it is possible to equalize temperature distribution of thesubstrate 62 which receives the heat of the light-emittingelements 63. Therefore, the thermal radiation property of thesubstrate 62 can be improved. In particular, by providing thesecond slits 112, which run along the direction perpendicular to the longitudinal direction of thesubstrate 62, between the adjacent thermallyradiative sheets 110, it is possible to suppress a warp and deformation of thesubstrate 62 due to heat. - Next, a process of manufacturing the light-emitting
device 61 will be explained hereinafter with reference toFIG. 13 to FIG. 15 . - First, the
first conductor pattern 70 and thesecond conductor pattern 71 are formed on thefirst surface 65a of thesubstrate 62. Specifically, the copper foil deposited on thefirst surface 65a is etched, and thereby copper layers 88 of the first and thesecond conductor pattern copper layer 88 of thefirst conductor pattern 70, parts which form thepads 72 are electrically connected to each other through thecopper layer 88 of thesecond conductor pattern 71.
Therefore, all the parts of thecopper layer 88 of thefirst conductor pattern 70, which form thepads 72, are maintained at the same potential. - In this state, the
copper layer 88 of thefirst conductor pattern 70 is subjected to electroplating, and thereby anickel plating layer 89 is formed on thecopper layer 88. Thereafter, thenickel plating layer 89 is subjected to electroplating, and thereby asilver plating layer 90 is formed on thenickel plating layer 89. In the step of performing electroplating, all the parts which form thepads 72 in thecopper layer 88 of thefirst conductor pattern 70 are maintained at the same potential. Therefore, thenickel plating layer 89 and thesilver plating layer 90 are formed on thecopper layer 88 of thefirst conductor pattern 70, by using thecopper layer 88 of thefirst conductor pattern 70 as cathode, using the same metal as plating layer as anode, and causing an electric current to flow between the cathode and the anode. Thenickel plating layer 89 and thesilver plating layer 90 are also formed on thecopper layer 88 of thesecond conductor pattern 71 simultaneously with thefirst conductor pattern 70. - Thereafter, as illustrated in
FIG. 14 , thecommon line 92 of thesecond conductor pattern 71 is removed from thefirst surface 65a of thesubstrate 62. Specifically, thecommon line 92 on thefirst surface 65a is scraped away in the same manner as the first embodiment. As a result, electrical connection between thepads 72 of thefirst conductor pattern 70 and thesecond conductor pattern 71 is severed, and thepads 72 are maintained in a state of being electrically independent. - Simultaneously with scraping away the
common line 92 from thefirst surface 65a, a groove-likedepressed part 105 is formed in thefirst surface 65a. Thedepressed part 105 has thecurved parts 106, which are curved to detour around the piercingparts 66, in positions corresponding to the piercingparts 66 of thesubstrate 62. - The
depressed part 105 crosses over the bases of thebranch lines 93 branching off from thecommon line 92. As a result, thebranch lines 93 are left on thefirst surface 65a of thesubstrate 62, in a state of being electrically separated from each other. - Thereafter, six light-emitting
elements 63 are affixed on each of the first and thesecond mounting areas pad 72. Then, the positive electrodes of the light-emittingelements 63 are electrically connected to thepads 72, to which the light-emittingelements 63 are affixed, by bondingwires 98. In the same manner, the negative electrodes of the light-emittingelements 63 are connected to thepower supply terminals 80 of theadjacent pads 72 and thepower supply terminals 85 of thepower supply patterns wires 99. - Then, the light-emitting
elements 63 arranged in two lines and thebonding wires pads 72 by the sealingmembers device 61 as illustrated inFIG. 15 is formed. - According to the third embodiment having the above structure, the
second conductor pattern 71 which maintains thepads 72 of thefirst conductor pattern 70 at the same potential is formed of thecommon line 92 and thebranch lines 93 which are branched off from thecommon line 92 and reach thepads 72. Therefore, electrical connection between thepads 72 obtained by thesecond conductor pattern 71 can be severed, by removing thecommon line 92 from thesubstrate 62. - Therefore, in the same manner as the first embodiment, it is possible to efficiently and easily perform the work of cutting off electrical connection between the
pads 72, and improve the productivity of the light-emittingdevice 61. - In addition, the
depressed part 105 which is left after thecommon line 92 is scraped away is distant from the end edge of thesubstrate 62 by the predetermined distance, and positioned between the end edge of thesubstrate 62 and thepads 72. As a result, the creepage distance between the end edge of thesubstrate 62 and thepads 72 becomes longer than the clearance between the end edge of thesubstrate 62 and thepads 72, by a length corresponding to the depth of thedepressed part 105, and it is possible to secure an insulating distance between the end edge of thesubstrate 62 and thepads 72. - In addition, according to the third embodiment, the
depressed part 105 has thecurved parts 106, which are curved to detour around the piercingparts 66, in positions corresponding to the piercingparts 66 of thesubstrate 62. Therefore, it is possible to equally secure insulating distances from the edges of the piercingparts 66 to thecurved parts 106, and increase the dielectric strength of thesubstrate 62. Thus, even when thescrews 68 inserted through the piercingparts 66 are formed of metal, insulation of thescrews 68 from thepads 72 can be sufficiently secured, and the reliability of electrical insulation of the light-emittingdevice 61 can be improved. -
FIG. 19 discloses a fourth embodiment. - The fourth embodiment is different from the third embodiment, in that a plurality of through-
holes 120 are provided in outer edge parts of asubstrate 62 running alonglong sides device 61 are the same as those of the third embodiment. - The through-
holes 120 of thesubstrate 62 are used for inserting screws which fix thesubstrate 62 to a base of an illumination device. The through-holes 120 are arranged at intervals in a longitudinal direction of thesubstrate 62. In addition, adepressed part 105 on afirst surface 65a of thesubstrate 62 has a plurality ofcurved parts 106 in positions corresponding to the through-holes 120. Thecurved parts 106 are curved in an arc shape in a direction going away from the end edge of thesubstrate 62, to detour around the through-holes 120. - Also in the fourth embodiment as described above, an insulating distance from the through-
holes 120 to thedepressed part 105 can be secured, by presence of thecurved parts 106. Therefore, the dielectric strength of thesubstrate 62 is improved, and it is possible to sufficiently secure insulation of the screws frompads 72, even when the screws inserted through the through-holes 120 are formed of metal. -
FIG. 20 to FIG. 24 disclose a fifth embodiment. - The fifth embodiment is different from the third embodiment, mainly in the shape of the second conductor pattern and the structure for cutting off electrical connection between pads obtained by the second conductor pattern. The basic structure of the substrate of the fifth embodiment other than these points is the same as that of the third embodiment. Therefore, in the fifth embodiment, constituent elements which are the same as those in the third embodiment are denoted by the same respective reference numerals as those of the third embodiment, and explanation thereof is omitted.
- As illustrated in
FIG. 20 , afirst conductor pattern 70 formed on afirst surface 65a of asubstrate 62 includes fourteenpads 72. Thepads 72 are arranged in line at intervals in a longitudinal direction of thesubstrate 62. - The fourteen
pads 72 are electrically connected by asecond conductor pattern 200 and maintained at the same potential, before thepads 72 are subjected to electroplating. Thesecond conductor pattern 200 is formed on thefirst surface 65a of thesubstrate 62. Thesecond conductor pattern 200 has arelay line 201, and a plurality of connection lines 202. As illustrated inFIG. 20 andFIG. 22 , therelay line 201 is positioned at the left end of thesubstrate 62, and extends along ashort side 62c of thesubstrate 62.
Therelay line 201 electrically connects thepad 72 located at the left end of thesubstrate 62 with thefirst conductor pattern 70. - The connection lines 202 are drawn from the
pads 72 and apower supply pattern 84a positioned at the right end of thesubstrate 62, and arranged between thepads 72 and along side 62a of thesubstrate 62. End parts of eachconnection line 202 located at the end reverse to thepad 72 is guided toward thelong side 62a of thesubstrate 62. According to the fifth embodiment, the end parts of theconnection lines 202 are assigned to removal positions P1, P2, P3 and P4 which are set in four positions of thelong side 62a of thesubstrate 62. The removal positions P1, P2, P3 and P4 are arranged at intervals in the longitudinal direction of thesubstrate 62. - Specifically, as illustrated in
FIG. 20 andFIG. 22 , the end parts of the fourconnection lines 202 which correspond to thefirst pad 72, located at the left end of thesubstrate 62, to thefourth pad 72 are guided to removal position P1 and collected therein. The end parts of the fourconnection lines 202 which correspond to thefifth pad 72 to theeighth pad 72 are guided to removal position P2 and collected therein. The end parts of the fourconnection lines 202 which correspond to theninth pad 72 to thetwelfth pad 72 are guided to removal position P3 and collected therein. The end parts of the twoconnection lines 202 which correspond to thethirteenth pad 72 to thefourteenth pad 72, and the end part of theconnection line 202 which corresponds to thepower supply pattern 84a are guided to removal position P4 and collected therein. The end parts of theconnection lines 202 guided to each of the removal positions P1, P2, P3 and P4 are electrically connected to each other. - In addition, in the fifth embodiment, a thermally
radiative sheet 203 is deposited on asecond surface 65b of thesubstrate 62. The thermallyradiative sheet 203 is an example of a conductor, and formed of metal material which has excellent heat conductance such as copper foil. The thermallyradiative sheet 203 covers the whole of thesecond surface 65b of thesubstrate 62. - The
second conductor pattern 200 becomes redundant after thepads 72 are subjected to electroplating. Therefore, in the fifth embodiment, after thepads 72 are subjected to electroplating, electrical connection between thepads 72 obtained by thesecond conductor pattern 200 is severed. - Specifically, part of the
short side 62c of thesubstrate 62 and the removal positions P1, P2, P3 and P4 of thelong side 62a of thesubstrate 62 are scraped away, and thereby therelay line 201 is severed, and the end parts of theconnection lines 202 are removed. Therefore, adepressed part 204 which is traces of scraping away the parts of thesubstrate 62 is formed in thesubstrate 62. Thedepressed part 204 includes first tofifth cutoff parts first cutoff part 204a is formed in theshort side 62c of thesubstrate 62. The second tofifth cutoff parts long side 62a of thesubstrate 62. - Each of the first to
fifth cutoff parts bottom surface 205a and aninternal periphery surface 205b, and is opened to thefirst surface 65a and the outerperipheral surface 65c of thesubstrate 62. Thebottom surface 205a connects to the outerperipheral surface 65c of thesubstrate 62. Therefore, the first tofifth cutoff parts substrate 62 in the thickness direction, and are positioned in corner parts defined by thefirst surface 65a and the outerperipheral surface 65c of thesubstrate 62. - By presence of the first to
fifth cutoff parts pads 72 are electrically separated from one another, although most of therelay line 201 and theconnection lines 202 are left on thefirst surface 65a of thesubstrate 62. In addition, as illustrated inFIG. 24 , a creepage distance between thefirst conductor pattern 70 on thefirst surface 65a of thesubstrate 62 and the thermallyradiative sheet 203 deposited on thesecond surface 65b of thesubstrate 62 is a value, which is obtained by adding the length of thebottom surface 204a of thedepressed part 204. Therefore, the creepage distance is longer than clearance between thefirst conductor pattern 70 on thefirst surface 65a of thesubstrate 62 and the thermallyradiative sheet 203 deposited on thesecond surface 65b by the length of thebottom surface 204a of the recessedpart 204. As a result, an insulation distance between thefirst conductor pattern 70 and the thermallyradiative sheet 203 can be sufficiently secured, and the dielectric strength of thesubstrate 62 is improved. - In the fifth embodiment, three through-
holes 206 are formed in the center part of thesubstrate 62. The through-holes 206 are used for inserting screws, which fix thesubstrate 62 to a base of an illumination device, and arranged at intervals in the longitudinal direction of thesubstrate 62. - According to the fifth embodiment as described above, electrical connection between all the
pads 72 can be removed, by scraping away the four parts of thelong side 62a of thesubstrate 62 and a part of theshort side 62c of thesubstrate 62. Therefore, the range of the part which is scraped away from thesubstrate 62 is remarkably reduced, in comparison with the first embodiment and the third embodiment. As a result, the work of removing thesecond conductor pattern 71 can be easily performed in a short time, and the manufacturing cost of thesubstrate 62 can be reduced. - Simultaneously, since the range of the part which is scraped away from the
substrate 62 is reduced, the quantity of grinding swarf which is generated when thesubstrate 62 is scraped is reduced. This reduces the possibility that grinding swarf adheres to thepads 72, and prevents deterioration in the workability when the light-emitting elements are affixed to thepads 72. - In the light-emitting devices of the first and the third embodiments, the light-emitting diode chips are mounted on the pads by the chip-on-board method. However, a light-emitting diode package obtained by combining a plurality of light-emitting diode chips may be mounted on the pads by the surface-mount method.
- Although the pads are preferably used as a power supply wiring pattern, they are not limited to use as wiring pattern. Specifically, when a reflecting layer is formed on the pads, the electrical-conduction function of the pads is not indispensable, and there are cases where the pads have only to exhibit a function of reflecting light emitted by the light-emitting elements, or a function as heat spreader which spreads heat generated by the light-emitting elements.
- In addition, it is not indispensable that the sealing members contain fluorescent material. For example, the red light, green light, or blue light emitted by the light-emitting elements may be directly radiated to the outside of the light-emitting device.
- The illumination device using the light-emitting devices is applicable to light-source devices of an electric light bulb type, illumination tools used indoors or outdoors such as spotlights, and displays.
- While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
- It is explicitly stated that all features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original disclosure as well as for the purpose of restricting the claimed invention independent of the composition of the features in the embodiments and/or the claims. It is explicitly stated that all value ranges or indications of groups of entities disclose every possible intermediate value or intermediate entity for the purpose of original disclosure as well as for the purpose of restricting the claimed invention, in particular as limits of value ranges.
Claims (11)
- A light-emitting device comprising:a substrate (2, 62);a plurality of pads (9, 72) arranged on the substrate (2, 62), each of the pads (9, 72) having electric conductance and a surface on which a reflecting layer (22, 90) formed by electroplating is provided;a plurality of light-emitting elements (3, 63) which are mounted on the pads (9, 72); anda depressed part (33, 105, 204) which is left on the substrate (2, 62), the depressed part (33, 105, 204) being formed on the substrate (2, 62) by removing a pattern (8, 71, 200) on the substrate (2, 62), by which the pads (9, 72) are electrically connected.
- The light-emitting device of claim 1, further comprising:a conductor pattern (7, 70) which supplies an electric current to the light-emitting elements (3, 63), the conductor pattern (7, 70) including the pads (9, 72) and being formed on the substrate (2, 62).
- The light-emitting device of claim 1 or 2, characterized in that
the depressed part (33, 105) extends along an edge of the substrate (2, 62) in a position distant from the edge of the substrate (2, 62). - The light-emitting device of any one of claims 1 to 3, characterized in that
the substrate (62) includes a piercing part (66) through which a fixing tool (68) is inserted, the piercing part (66) is positioned between the edge of the substrate (62) and the depressed part (105), and the depressed part (105) includes a part (106) which detours around the piercing part (68) in a position corresponding to the piercing part (68). - The light-emitting device of any one of claims 1 to 4, characterized in that
the substrate (2, 62) has electric insulating property, and the depressed part (33, 105, 204) has a bottom. - The light-emitting device of any one of claims 1 to 5, characterized in that
the pattern (71) includes a plurality of connection lines (202) which are guided from the pads (72) to a plurality of positions on the substrate (62), the depressed part (204) includes a plurality of cutoff parts (204b, 204c, 204d, 204e) formed in the positions to which the connection lines (202) are guided, and the cutoff parts (204b, 204c, 204d, 204e) are opened to an edge of the substrate and distant from one another. - The light-emitting device of any one of claims 1 to 6, characterized in that
the substrate (71) includes a first surface (65a) on which the pads (72) and the connection lines (202) are arranged, a second surface (65b) which is positioned on a side opposite to the first surface (65a), and an outer peripheral surface (65c) which connects the first surface (65a) with the second surface (65b), and each of the cutoff parts (204b, 204c, 204d, 204e) is opened to a corner part of the substrate (62) which is defined by the first surface (65a) and the outer peripheral surface (65c), and has a bottom which connects to the outer peripheral surface (65c). - The light-emitting device of claim 7, characterized in that
a conductor (110, 203) is deposited on the second surface of the substrate (62). - A method of manufacturing a light-emitting device, comprising:forming a plurality of pads (9, 72) which have electric conductance, and a pattern (8, 71, 200) which electrically connects the pads (9, 72), on a substrate (2, 62);forming a reflecting layer (22, 90) on surfaces of the pads (9, 72) by subjecting the pads (9, 72) to electroplating;removing the pattern (8, 71, 200) from the substrate (2, 62) after the reflecting layer (22, 90) is formed on the pads (9, 72); andmounting a plurality of light-emitting elements (3, 63) on the pads (9, 72) .
- The method of claim 9, characterized in that a depressed part (33, 105, 204) is formed on the substrate (62) when the pattern (B, 71, 200) is removed from the substrate (2, 62).
- An illumination device comprising:a main body (42, 52); anda light-emitting device (1) according to any one of claims 1 to 8 and supported by the main body (42, 52).
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2009249934 | 2009-10-30 | ||
JP2010029541 | 2010-02-12 | ||
JP2010232291A JP2011187922A (en) | 2009-10-30 | 2010-10-15 | Light emitting device, method of manufacturing light emitting device, and illumination device |
Publications (2)
Publication Number | Publication Date |
---|---|
EP2317552A2 true EP2317552A2 (en) | 2011-05-04 |
EP2317552A3 EP2317552A3 (en) | 2013-07-31 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP10189480.6A Withdrawn EP2317552A3 (en) | 2009-10-30 | 2010-10-29 | Light-emitting device, method of manufacturing light-emitting device, and illumination device |
Country Status (4)
Country | Link |
---|---|
US (1) | US8816381B2 (en) |
EP (1) | EP2317552A3 (en) |
JP (1) | JP2011187922A (en) |
CN (1) | CN102097422A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP3579272A1 (en) * | 2018-06-05 | 2019-12-11 | InnoLux Corporation | Electronic device |
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JP5817297B2 (en) * | 2011-06-03 | 2015-11-18 | 東芝ライテック株式会社 | Light emitting device and lighting device |
JP5812845B2 (en) * | 2011-12-19 | 2015-11-17 | 新光電気工業株式会社 | Light-emitting element mounting package, light-emitting element package, and manufacturing method thereof |
US20140168961A1 (en) * | 2012-12-18 | 2014-06-19 | Jack Guy Dubord | Retrofit kit for fluorescent lamp fixtures |
JP2014146661A (en) * | 2013-01-28 | 2014-08-14 | Panasonic Corp | Light emitting module, illumination device and luminaire |
TWI598665B (en) * | 2013-03-15 | 2017-09-11 | 隆達電子股份有限公司 | Luminous element, bar-type luminous element and applications thereof |
TWI512235B (en) * | 2013-07-08 | 2015-12-11 | Lediamond Opto Corp | Illuminant device |
JP2015109215A (en) * | 2013-12-05 | 2015-06-11 | パナソニックIpマネジメント株式会社 | Light source unit and lighting fixture using the same |
DE202014100686U1 (en) * | 2014-02-17 | 2015-06-01 | Zumtobel Lighting Gmbh | Printed circuit board with special coupling areas |
JP6500223B2 (en) * | 2014-04-17 | 2019-04-17 | パナソニックIpマネジメント株式会社 | Light source device and projection type image display device |
JP7165857B2 (en) * | 2018-09-03 | 2022-11-07 | 日亜化学工業株式会社 | light emitting device |
CN214409385U (en) * | 2021-02-05 | 2021-10-15 | 台达电子工业股份有限公司 | Optical transceiver module |
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JP2008251618A (en) | 2007-03-29 | 2008-10-16 | Citizen Electronics Co Ltd | Light-emitting diode and manufacturing process of the same |
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- 2010-10-15 JP JP2010232291A patent/JP2011187922A/en not_active Withdrawn
- 2010-10-26 US US12/912,434 patent/US8816381B2/en not_active Expired - Fee Related
- 2010-10-29 CN CN201010533674XA patent/CN102097422A/en active Pending
- 2010-10-29 EP EP10189480.6A patent/EP2317552A3/en not_active Withdrawn
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JP2009054989A (en) | 2007-07-31 | 2009-03-12 | Sharp Corp | Light-emitting apparatus, illuminating apparatus, and clean room having the illuminating apparatus |
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EP3579272A1 (en) * | 2018-06-05 | 2019-12-11 | InnoLux Corporation | Electronic device |
Also Published As
Publication number | Publication date |
---|---|
CN102097422A (en) | 2011-06-15 |
US20110101384A1 (en) | 2011-05-05 |
EP2317552A3 (en) | 2013-07-31 |
US8816381B2 (en) | 2014-08-26 |
JP2011187922A (en) | 2011-09-22 |
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